diff --git a/src/ca-module.cpp b/src/ca-module.cpp
index cd28b94..c2072dd 100644
--- a/src/ca-module.cpp
+++ b/src/ca-module.cpp
@@ -35,7 +35,6 @@
 #include <ndn-cxx/util/random.hpp>
 #include <ndn-cxx/util/string-helper.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
@@ -44,7 +43,7 @@
 
 NDN_LOG_INIT(ndncert.ca);
 
-CaModule::CaModule(Face& face, security::KeyChain& keyChain,
+CaModule::CaModule(ndn::Face& face, ndn::KeyChain& keyChain,
                    const std::string& configPath, const std::string& storageType)
   : m_face(face)
   , m_keyChain(keyChain)
@@ -52,7 +51,7 @@
   // load the config and create storage
   m_config.load(configPath);
   m_storage = CaStorage::createCaStorage(storageType, m_config.caProfile.caPrefix, "");
-  random::generateSecureBytes(m_requestIdGenKey, 32);
+  ndn::random::generateSecureBytes(m_requestIdGenKey, 32);
   if (m_config.nameAssignmentFuncs.size() == 0) {
     m_config.nameAssignmentFuncs.push_back(NameAssignmentFunc::createNameAssignmentFunc("random"));
   }
@@ -80,7 +79,7 @@
     prefix,
     [&] (const Name& name) {
       // register INFO RDR metadata prefix
-      name::Component metaDataComp(32, reinterpret_cast<const uint8_t*>("metadata"), std::strlen("metadata"));
+      ndn::name::Component metaDataComp(32, reinterpret_cast<const uint8_t*>("metadata"), std::strlen("metadata"));
       auto filterId = m_face.setInterestFilter(Name(name).append("INFO").append(metaDataComp),
                                                [this] (auto&&, const auto& i) { onCaProfileDiscovery(i); });
       m_interestFilterHandles.push_back(filterId);
@@ -126,36 +125,29 @@
     const auto& cert = identity.getDefaultKey().getDefaultCertificate();
     Block contentTLV = infotlv::encodeDataContent(m_config.caProfile, cert);
 
-    // set naming convention to be typed
-    auto convention = name::getConventionEncoding();
-    name::setConventionEncoding(name::Convention::TYPED);
-
     Name infoPacketName(m_config.caProfile.caPrefix);
-    auto segmentComp = name::Component::fromSegment(0);
+    auto segmentComp = ndn::name::Component::fromSegment(0);
     infoPacketName.append("CA").append("INFO").appendVersion().append(segmentComp);
     m_profileData = std::make_unique<Data>(infoPacketName);
     m_profileData->setFinalBlock(segmentComp);
     m_profileData->setContent(contentTLV);
     m_profileData->setFreshnessPeriod(DEFAULT_DATA_FRESHNESS_PERIOD);
     m_keyChain.sign(*m_profileData, signingByIdentity(m_config.caProfile.caPrefix));
-
-    // set back the convention
-    name::setConventionEncoding(convention);
   }
   return *m_profileData;
 }
 
 void
-CaModule::onCaProfileDiscovery(const Interest& request)
+CaModule::onCaProfileDiscovery(const Interest&)
 {
   NDN_LOG_TRACE("Received CA Profile MetaData discovery Interest");
   if (m_profileData == nullptr) {
     m_profileData = std::make_unique<Data>(getCaProfileData());
   }
-  MetadataObject metadata;
+  ndn::MetadataObject metadata;
   metadata.setVersionedName(m_profileData->getName().getPrefix(-1));
   Name discoveryInterestName(m_profileData->getName().getPrefix(-2));
-  name::Component metadataComponent(32, reinterpret_cast<const uint8_t*>("metadata"), std::strlen("metadata"));
+  ndn::name::Component metadataComponent(32, reinterpret_cast<const uint8_t*>("metadata"), std::strlen("metadata"));
   discoveryInterestName.append(metadataComponent);
   m_face.put(metadata.makeData(discoveryInterestName, m_keyChain, signingByIdentity(m_config.caProfile.caPrefix)));
 }
@@ -168,7 +160,7 @@
 
   // process PROBE requests: collect probe parameters
   auto parameters = probetlv::decodeApplicationParameters(request.getApplicationParameters());
-  std::vector <PartialName> availableComponents;
+  std::vector<ndn::PartialName> availableComponents;
   for (auto& item : m_config.nameAssignmentFuncs) {
     auto names = item->assignName(parameters);
     availableComponents.insert(availableComponents.end(), names.begin(), names.end());
@@ -216,7 +208,7 @@
   // get ECDH pub key and cert request
   const auto& parameterTLV = request.getApplicationParameters();
   std::vector <uint8_t> ecdhPub;
-  shared_ptr <security::Certificate> clientCert;
+  std::shared_ptr<Certificate> clientCert;
   try {
     requesttlv::decodeApplicationParameters(parameterTLV, requestType, ecdhPub, clientCert);
   }
@@ -256,7 +248,7 @@
 
   // verify identity name
   if (!m_config.caProfile.caPrefix.isPrefixOf(clientCert->getIdentity())
-      || !security::Certificate::isValidName(clientCert->getName())
+      || !Certificate::isValidName(clientCert->getName())
       || clientCert->getIdentity().size() <= m_config.caProfile.caPrefix.size()) {
     NDN_LOG_ERROR("An invalid certificate name is being requested " << clientCert->getName());
     m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::NAME_NOT_ALLOWED,
@@ -286,13 +278,13 @@
     }
 
     // verify signature
-    if (!security::verifySignature(*clientCert, *clientCert)) {
+    if (!ndn::security::verifySignature(*clientCert, *clientCert)) {
       NDN_LOG_ERROR("Invalid signature in the self-signed certificate.");
       m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::BAD_SIGNATURE,
                                          "Invalid signature in the self-signed certificate."));
       return;
     }
-    if (!security::verifySignature(request, *clientCert)) {
+    if (!ndn::security::verifySignature(request, *clientCert)) {
       NDN_LOG_ERROR("Invalid signature in the Interest packet.");
       m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::BAD_SIGNATURE,
                                          "Invalid signature in the Interest packet."));
@@ -301,7 +293,7 @@
   }
   else if (requestType == RequestType::REVOKE) {
     //verify cert is from this CA
-    if (!security::verifySignature(*clientCert, caCert)) {
+    if (!ndn::security::verifySignature(*clientCert, caCert)) {
       NDN_LOG_ERROR("Invalid signature in the certificate to revoke.");
       m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::BAD_SIGNATURE,
                                          "Invalid signature in the certificate to revoke."));
@@ -331,7 +323,7 @@
   requestState.cert = *clientCert;
   // generate salt for HKDF
   std::array<uint8_t, 32> salt;
-  random::generateSecureBytes(salt.data(), salt.size());
+  ndn::random::generateSecureBytes(salt.data(), salt.size());
   // hkdf
   std::array<uint8_t, 16> aesKey;
   hkdf(sharedSecret.data(), sharedSecret.size(), salt.data(), salt.size(),
@@ -340,7 +332,7 @@
   try {
     m_storage->addRequest(requestState);
   }
-  catch (const std::runtime_error& e) {
+  catch (const std::runtime_error&) {
     NDN_LOG_ERROR("Duplicate Request ID: The same request has been seen before.");
     m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::INVALID_PARAMETER,
                                        "Duplicate Request ID: The same request has been seen before."));
@@ -371,14 +363,14 @@
     return;
   }
   // verify signature
-  if (!security::verifySignature(request, requestState->cert)) {
+  if (!ndn::security::verifySignature(request, requestState->cert)) {
     NDN_LOG_ERROR("Invalid Signature in the Interest packet.");
     m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::BAD_SIGNATURE,
                                        "Invalid Signature in the Interest packet."));
     return;
   }
   // decrypt the parameters
-  Buffer paramTLVPayload;
+  ndn::Buffer paramTLVPayload;
   try {
     paramTLVPayload = decodeBlockWithAesGcm128(request.getApplicationParameters(), requestState->encryptionKey.data(),
                                                requestState->requestId.data(), requestState->requestId.size(),
@@ -398,7 +390,7 @@
                                        "No parameters are found after decryption."));
     return;
   }
-  Block paramTLV = makeBinaryBlock(tlv::EncryptedPayload, paramTLVPayload.data(), paramTLVPayload.size());
+  auto paramTLV = ndn::makeBinaryBlock(tlv::EncryptedPayload, paramTLVPayload.data(), paramTLVPayload.size());
   paramTLV.parse();
 
   // load the corresponding challenge module
@@ -457,22 +449,22 @@
   }
 }
 
-security::Certificate
+Certificate
 CaModule::issueCertificate(const RequestState& requestState)
 {
   auto expectedPeriod = requestState.cert.getValidityPeriod().getPeriod();
-  security::ValidityPeriod period(expectedPeriod.first, expectedPeriod.second);
-  security::Certificate newCert;
+  ndn::security::ValidityPeriod period(expectedPeriod.first, expectedPeriod.second);
+  Certificate newCert;
 
   Name certName = requestState.cert.getKeyName();
-  certName.append("NDNCERT").append(std::to_string(random::generateSecureWord64()));
+  certName.append("NDNCERT").append(ndn::to_string(ndn::random::generateSecureWord64()));
   newCert.setName(certName);
   newCert.setContent(requestState.cert.getContent());
   NDN_LOG_TRACE("cert request content " << requestState.cert);
   SignatureInfo signatureInfo;
   signatureInfo.setValidityPeriod(period);
-  security::SigningInfo signingInfo(security::SigningInfo::SIGNER_TYPE_ID,
-                                    m_config.caProfile.caPrefix, signatureInfo);
+  ndn::security::SigningInfo signingInfo(ndn::security::SigningInfo::SIGNER_TYPE_ID,
+                                         m_config.caProfile.caPrefix, signatureInfo);
 
   m_keyChain.sign(newCert, signingInfo);
   NDN_LOG_TRACE("new cert got signed" << newCert);
@@ -492,7 +484,7 @@
     return nullptr;
   }
   try {
-    NDN_LOG_TRACE("Request Id to query the database " << toHex(requestId.data(), requestId.size()));
+    NDN_LOG_TRACE("Request Id to query the database " << ndn::toHex(requestId.data(), requestId.size()));
     return std::make_unique<RequestState>(m_storage->getRequest(requestId));
   }
   catch (const std::exception& e) {
@@ -520,4 +512,3 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/ca-module.hpp b/src/ca-module.hpp
index e98638b..88af9f1 100644
--- a/src/ca-module.hpp
+++ b/src/ca-module.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -25,7 +25,9 @@
 #include "detail/crypto-helpers.hpp"
 #include "detail/ca-storage.hpp"
 
-namespace ndn {
+#include <ndn-cxx/face.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
+
 namespace ndncert {
 namespace ca {
 
@@ -37,12 +39,12 @@
  *
  * @param RequestState The state of the certificate request whose status is updated.
  */
-using StatusUpdateCallback = function<void(const RequestState&)>;
+using StatusUpdateCallback = std::function<void(const RequestState&)>;
 
-class CaModule : noncopyable
+class CaModule : boost::noncopyable
 {
 public:
-  CaModule(Face& face, security::KeyChain& keyChain, const std::string& configPath,
+  CaModule(ndn::Face& face, ndn::KeyChain& keyChain, const std::string& configPath,
            const std::string& storageType = "ca-storage-sqlite3");
 
   ~CaModule();
@@ -53,7 +55,7 @@
     return m_config;
   }
 
-  const unique_ptr<CaStorage>&
+  const std::unique_ptr<CaStorage>&
   getCaStorage()
   {
     return m_storage;
@@ -84,7 +86,7 @@
   std::unique_ptr<RequestState>
   getCertificateRequest(const Interest& request);
 
-  security::Certificate
+  Certificate
   issueCertificate(const RequestState& requestState);
 
   void
@@ -94,10 +96,10 @@
   generateErrorDataPacket(const Name& name, ErrorCode error, const std::string& errorInfo);
 
 NDNCERT_PUBLIC_WITH_TESTS_ELSE_PRIVATE:
-  Face& m_face;
+  ndn::Face& m_face;
   CaConfig m_config;
-  unique_ptr<CaStorage> m_storage;
-  security::KeyChain& m_keyChain;
+  std::unique_ptr<CaStorage> m_storage;
+  ndn::KeyChain& m_keyChain;
   uint8_t m_requestIdGenKey[32];
   std::unique_ptr<Data> m_profileData;
   /**
@@ -105,12 +107,11 @@
    */
   StatusUpdateCallback m_statusUpdateCallback;
 
-  std::list<RegisteredPrefixHandle> m_registeredPrefixHandles;
-  std::list<InterestFilterHandle> m_interestFilterHandles;
+  std::list<ndn::RegisteredPrefixHandle> m_registeredPrefixHandles;
+  std::list<ndn::InterestFilterHandle> m_interestFilterHandles;
 };
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_CA_MODULE_HPP
diff --git a/src/challenge/challenge-email.cpp b/src/challenge/challenge-email.cpp
index 41d53d6..bc624bc 100644
--- a/src/challenge/challenge-email.cpp
+++ b/src/challenge/challenge-email.cpp
@@ -22,7 +22,6 @@
 #include <regex>
 #include <boost/process.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 NDN_LOG_INIT(ndncert.challenge.email);
@@ -37,8 +36,8 @@
 ChallengeEmail::ChallengeEmail(const std::string& scriptPath,
                                const size_t& maxAttemptTimes,
                                const time::seconds secretLifetime)
-    : ChallengeModule("email", maxAttemptTimes, secretLifetime)
-    , m_sendEmailScript(scriptPath)
+  : ChallengeModule("email", maxAttemptTimes, secretLifetime)
+  , m_sendEmailScript(scriptPath)
 {
 }
 
@@ -52,7 +51,8 @@
     // for the first time, init the challenge
     std::string emailAddress = readString(params.get(tlv::ParameterValue));
     if (!isValidEmailAddress(emailAddress)) {
-      return returnWithNewChallengeStatus(request, INVALID_EMAIL, JsonSection(), m_maxAttemptTimes - 1, m_secretLifetime);
+      return returnWithNewChallengeStatus(request, INVALID_EMAIL, JsonSection(), m_maxAttemptTimes - 1,
+                                          m_secretLifetime);
     }
     auto lastComponentRequested = readString(request.cert.getIdentity().get(-1));
     if (lastComponentRequested != emailAddress) {
@@ -64,8 +64,10 @@
     secretJson.add(PARAMETER_KEY_CODE, emailCode);
     // send out the email
     sendEmail(emailAddress, emailCode, request);
-    NDN_LOG_TRACE("Secret for request " << toHex(request.requestId.data(), request.requestId.size()) << " : " << emailCode);
-    return returnWithNewChallengeStatus(request, NEED_CODE, std::move(secretJson), m_maxAttemptTimes, m_secretLifetime);
+    NDN_LOG_TRACE("Secret for request " << ndn::toHex(request.requestId.data(), request.requestId.size())
+                  << " : " << emailCode);
+    return returnWithNewChallengeStatus(request, NEED_CODE, std::move(secretJson),
+                                        m_maxAttemptTimes, m_secretLifetime);
   }
   if (request.challengeState) {
     if (request.challengeState->challengeStatus == NEED_CODE ||
@@ -134,17 +136,17 @@
     if (params.size() != 1 || params.find(PARAMETER_KEY_EMAIL) == params.end()) {
       NDN_THROW(std::runtime_error("Wrong parameter provided."));
     }
-    request.push_back(makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
-    request.push_back(makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_EMAIL));
-    request.push_back(makeStringBlock(tlv::ParameterValue, params.find(PARAMETER_KEY_EMAIL)->second));
+    request.push_back(ndn::makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
+    request.push_back(ndn::makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_EMAIL));
+    request.push_back(ndn::makeStringBlock(tlv::ParameterValue, params.find(PARAMETER_KEY_EMAIL)->second));
   }
   else if (status == Status::CHALLENGE && (challengeStatus == NEED_CODE || challengeStatus == WRONG_CODE)) {
     if (params.size() != 1 || params.find(PARAMETER_KEY_CODE) == params.end()) {
       NDN_THROW(std::runtime_error("Wrong parameter provided."));
     }
-    request.push_back(makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
-    request.push_back(makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_CODE));
-    request.push_back(makeStringBlock(tlv::ParameterValue, params.find(PARAMETER_KEY_CODE)->second));
+    request.push_back(ndn::makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
+    request.push_back(ndn::makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_CODE));
+    request.push_back(ndn::makeStringBlock(tlv::ParameterValue, params.find(PARAMETER_KEY_CODE)->second));
   }
   else {
     NDN_THROW(std::runtime_error("Unexpected status or challenge status."));
@@ -179,4 +181,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/challenge/challenge-email.hpp b/src/challenge/challenge-email.hpp
index e2c7267..c5d76de 100644
--- a/src/challenge/challenge-email.hpp
+++ b/src/challenge/challenge-email.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "challenge-module.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 /**
@@ -88,6 +87,5 @@
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_CHALLENGE_EMAIL_HPP
diff --git a/src/challenge/challenge-module.cpp b/src/challenge/challenge-module.cpp
index f184ca9..bf3b966 100644
--- a/src/challenge/challenge-module.cpp
+++ b/src/challenge/challenge-module.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -21,7 +21,6 @@
 #include "challenge/challenge-module.hpp"
 #include <ndn-cxx/util/random.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 ChallengeModule::ChallengeModule(const std::string& challengeType,
@@ -41,7 +40,7 @@
   return i == factory.end() ? false : true;
 }
 
-unique_ptr<ChallengeModule>
+std::unique_ptr<ChallengeModule>
 ChallengeModule::createChallengeModule(const std::string& challengeType)
 {
   ChallengeFactory& factory = getFactory();
@@ -61,11 +60,11 @@
 {
   uint32_t securityCode = 0;
   do {
-    securityCode = random::generateSecureWord32();
+    securityCode = ndn::random::generateSecureWord32();
   }
   while (securityCode >= 4294000000);
   securityCode /= 4294;
-  std::string result = std::to_string(securityCode);
+  std::string result = ndn::to_string(securityCode);
   while (result.length() < 6) {
     result = "0" + result;
   }
@@ -103,4 +102,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/challenge/challenge-module.hpp b/src/challenge/challenge-module.hpp
index 9d7d859..1e33bfc 100644
--- a/src/challenge/challenge-module.hpp
+++ b/src/challenge/challenge-module.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,16 +23,16 @@
 
 #include "detail/ca-request-state.hpp"
 
-namespace ndn {
 namespace ndncert {
 
-class ChallengeModule : noncopyable
+class ChallengeModule : boost::noncopyable
 {
 public:
   explicit
   ChallengeModule(const std::string& challengeType, size_t maxAttemptTimes, time::seconds secretLifetime);
 
-  virtual ~ChallengeModule() = default;
+  virtual
+  ~ChallengeModule() = default;
 
   template <class ChallengeType>
   static void
@@ -46,7 +46,7 @@
   static bool
   isChallengeSupported(const std::string& challengeType);
 
-  static unique_ptr<ChallengeModule>
+  static std::unique_ptr<ChallengeModule>
   createChallengeModule(const std::string& challengeType);
 
   // For CA
@@ -83,7 +83,7 @@
   const time::seconds m_secretLifetime;
 
 private:
-  typedef function<unique_ptr<ChallengeModule>()> ChallengeCreateFunc;
+  typedef std::function<std::unique_ptr<ChallengeModule>()> ChallengeCreateFunc;
   typedef std::map<std::string, ChallengeCreateFunc> ChallengeFactory;
 
   static ChallengeFactory&
@@ -91,15 +91,15 @@
 };
 
 #define NDNCERT_REGISTER_CHALLENGE(C, T)                              \
-  static class NdnCert##C##ChallengeRegistrationClass {               \
+  static class NdnCert##C##ChallengeRegistrationClass                 \
+  {                                                                   \
   public:                                                             \
     NdnCert##C##ChallengeRegistrationClass()                          \
     {                                                                 \
-      ::ndn::ndncert::ChallengeModule::registerChallengeModule<C>(T); \
+      ::ndncert::ChallengeModule::registerChallengeModule<C>(T);      \
     }                                                                 \
   } g_NdnCert##C##ChallengeRegistrationVariable
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_CHALLENGE_MODULE_HPP
diff --git a/src/challenge/challenge-pin.cpp b/src/challenge/challenge-pin.cpp
index 5d3ea8a..6e42969 100644
--- a/src/challenge/challenge-pin.cpp
+++ b/src/challenge/challenge-pin.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,9 +19,9 @@
  */
 
 #include "challenge-pin.hpp"
+
 #include <ndn-cxx/util/random.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 NDN_LOG_INIT(ndncert.challenge.pin);
@@ -32,7 +32,7 @@
 const std::string ChallengePin::PARAMETER_KEY_CODE = "code";
 
 ChallengePin::ChallengePin(const size_t& maxAttemptTimes, const time::seconds& secretLifetime)
-    : ChallengeModule("pin", maxAttemptTimes, secretLifetime)
+  : ChallengeModule("pin", maxAttemptTimes, secretLifetime)
 {
 }
 
@@ -48,8 +48,10 @@
     std::string secretCode = generateSecretCode();
     JsonSection secretJson;
     secretJson.add(PARAMETER_KEY_CODE, secretCode);
-    NDN_LOG_TRACE("Secret for request " << toHex(request.requestId.data(), request.requestId.size()) << " : " << secretCode);
-    return returnWithNewChallengeStatus(request, NEED_CODE, std::move(secretJson), m_maxAttemptTimes, m_secretLifetime);
+    NDN_LOG_TRACE("Secret for request " << ndn::toHex(request.requestId.data(), request.requestId.size())
+                  << " : " << secretCode);
+    return returnWithNewChallengeStatus(request, NEED_CODE, std::move(secretJson), m_maxAttemptTimes,
+                                        m_secretLifetime);
   }
   if (request.challengeState) {
     if (request.challengeState->challengeStatus == NEED_CODE ||
@@ -109,15 +111,15 @@
 {
   Block request(tlv::EncryptedPayload);
   if (status == Status::BEFORE_CHALLENGE) {
-    request.push_back(makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
+    request.push_back(ndn::makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
   }
   else if (status == Status::CHALLENGE && (challengeStatus == NEED_CODE || challengeStatus == WRONG_CODE)) {
     if (params.size() != 1 || params.find(PARAMETER_KEY_CODE) == params.end()) {
       NDN_THROW(std::runtime_error("Wrong parameter provided."));
     }
-    request.push_back(makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
-    request.push_back(makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_CODE));
-    request.push_back(makeStringBlock(tlv::ParameterValue, params.find(PARAMETER_KEY_CODE)->second));
+    request.push_back(ndn::makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
+    request.push_back(ndn::makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_CODE));
+    request.push_back(ndn::makeStringBlock(tlv::ParameterValue, params.find(PARAMETER_KEY_CODE)->second));
   }
   else {
     NDN_THROW(std::runtime_error("Unexpected status or challenge status."));
@@ -125,5 +127,5 @@
   request.encode();
   return request;
 }
+
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/challenge/challenge-pin.hpp b/src/challenge/challenge-pin.hpp
index 61e0fb6..cfcf508 100644
--- a/src/challenge/challenge-pin.hpp
+++ b/src/challenge/challenge-pin.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "challenge-module.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 /**
@@ -70,6 +69,5 @@
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_CHALLENGE_PIN_HPP
diff --git a/src/challenge/challenge-possession.cpp b/src/challenge/challenge-possession.cpp
index ef93d25..a7f0f77 100644
--- a/src/challenge/challenge-possession.cpp
+++ b/src/challenge/challenge-possession.cpp
@@ -27,7 +27,6 @@
 
 #include <boost/property_tree/json_parser.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 NDN_LOG_INIT(ndncert.challenge.possession);
@@ -58,7 +57,7 @@
   }
   catch (const boost::property_tree::file_parser_error& error) {
     NDN_THROW(std::runtime_error("Failed to parse configuration file " + m_configFile + ": " +
-                                 error.message() + " on line " + std::to_string(error.line())));
+                                 error.message() + " on line " + ndn::to_string(error.line())));
   }
 
   if (config.begin() == config.end()) {
@@ -70,7 +69,7 @@
   auto it = anchorList.begin();
   for (; it != anchorList.end(); it++) {
     std::istringstream ss(it->second.get("certificate", ""));
-    auto cert = io::load<security::Certificate>(ss);
+    auto cert = ndn::io::load<Certificate>(ss);
     if (cert == nullptr) {
       NDN_LOG_ERROR("Cannot load the certificate from config file");
       continue;
@@ -87,7 +86,7 @@
   if (m_trustAnchors.empty()) {
     parseConfigFile();
   }
-  security::Certificate credential;
+  Certificate credential;
   const uint8_t* signature = nullptr;
   size_t signatureLen = 0;
   const auto& elements = params.elements();
@@ -113,16 +112,18 @@
   // verify the credential and the self-signed cert
   if (request.status == Status::BEFORE_CHALLENGE) {
     NDN_LOG_TRACE("Challenge Interest arrives. Check certificate and init the challenge");
+    using ndn::toHex;
+
     // check the certificate
     bool checkOK = false;
     if (credential.hasContent() && signatureLen == 0) {
       Name signingKeyName = credential.getSignatureInfo().getKeyLocator().getName();
-      security::transform::PublicKey key;
+      ndn::security::transform::PublicKey key;
       const auto& pubKeyBuffer = credential.getPublicKey();
       key.loadPkcs8(pubKeyBuffer.data(), pubKeyBuffer.size());
       for (auto anchor : m_trustAnchors) {
         if (anchor.getKeyName() == signingKeyName) {
-          if (security::verifySignature(credential, anchor)) {
+          if (ndn::security::verifySignature(credential, anchor)) {
             checkOK = true;
           }
         }
@@ -137,7 +138,7 @@
 
     // for the first time, init the challenge
     std::array<uint8_t, 16> secretCode{};
-    random::generateSecureBytes(secretCode.data(), 16);
+    ndn::random::generateSecureBytes(secretCode.data(), 16);
     JsonSection secretJson;
     secretJson.add(PARAMETER_KEY_NONCE, toHex(secretCode.data(), 16));
     auto credential_block = credential.wireEncode();
@@ -152,14 +153,14 @@
     if (credential.hasContent() || signatureLen == 0) {
       return returnWithError(request, ErrorCode::BAD_INTEREST_FORMAT, "Cannot find certificate");
     }
-    credential = security::Certificate(Block(fromHex(request.challengeState->secrets.get(PARAMETER_KEY_CREDENTIAL_CERT, ""))));
-    auto secretCode = *fromHex(request.challengeState->secrets.get(PARAMETER_KEY_NONCE, ""));
+    credential = Certificate(Block(ndn::fromHex(request.challengeState->secrets.get(PARAMETER_KEY_CREDENTIAL_CERT, ""))));
+    auto secretCode = *ndn::fromHex(request.challengeState->secrets.get(PARAMETER_KEY_NONCE, ""));
 
     //check the proof
-    security::transform::PublicKey key;
+    ndn::security::transform::PublicKey key;
     const auto& pubKeyBuffer = credential.getPublicKey();
     key.loadPkcs8(pubKeyBuffer.data(), pubKeyBuffer.size());
-    if (security::verifySignature({{secretCode.data(), secretCode.size()}}, signature, signatureLen, key)) {
+    if (ndn::security::verifySignature({{secretCode.data(), secretCode.size()}}, signature, signatureLen, key)) {
       return returnWithSuccess(request);
     }
     return returnWithError(request, ErrorCode::INVALID_PARAMETER,
@@ -196,10 +197,10 @@
     if (params.size() != 1) {
       NDN_THROW(std::runtime_error("Wrong parameter provided."));
     }
-    request.push_back(makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
+    request.push_back(ndn::makeStringBlock(tlv::SelectedChallenge, CHALLENGE_TYPE));
     for (const auto& item : params) {
       if (std::get<0>(item) == PARAMETER_KEY_CREDENTIAL_CERT) {
-        request.push_back(makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_CREDENTIAL_CERT));
+        request.push_back(ndn::makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_CREDENTIAL_CERT));
         Block valueBlock(tlv::ParameterValue);
         auto& certTlvStr = std::get<1>(item);
         valueBlock.push_back(Block(reinterpret_cast<const uint8_t*>(certTlvStr.data()), certTlvStr.size()));
@@ -210,17 +211,17 @@
       }
     }
   }
-  else if (status == Status::CHALLENGE && challengeStatus == NEED_PROOF){
+  else if (status == Status::CHALLENGE && challengeStatus == NEED_PROOF) {
     if (params.size() != 1) {
       NDN_THROW(std::runtime_error("Wrong parameter provided."));
     }
     for (const auto& item : params) {
       if (std::get<0>(item) == PARAMETER_KEY_PROOF) {
-        request.push_back(makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_PROOF));
+        request.push_back(ndn::makeStringBlock(tlv::ParameterKey, PARAMETER_KEY_PROOF));
         auto& sigTlvStr = std::get<1>(item);
-        Block valueBlock = makeBinaryBlock(tlv::ParameterValue,
-                                           reinterpret_cast<const uint8_t*>(sigTlvStr.data()),
-                                           sigTlvStr.size());
+        auto valueBlock = ndn::makeBinaryBlock(tlv::ParameterValue,
+                                               reinterpret_cast<const uint8_t*>(sigTlvStr.data()),
+                                               sigTlvStr.size());
         request.push_back(valueBlock);
       }
       else {
@@ -237,14 +238,14 @@
 
 void
 ChallengePossession::fulfillParameters(std::multimap<std::string, std::string>& params,
-                                       KeyChain& keyChain, const Name& issuedCertName,
+                                       ndn::KeyChain& keyChain, const Name& issuedCertName,
                                        const std::array<uint8_t, 16>& nonce)
 {
-  auto keyName = security::extractKeyNameFromCertName(issuedCertName);
-  auto id = keyChain.getPib().getIdentity(security::extractIdentityFromCertName(issuedCertName));
+  auto keyName = ndn::security::extractKeyNameFromCertName(issuedCertName);
+  auto id = keyChain.getPib().getIdentity(ndn::security::extractIdentityFromCertName(issuedCertName));
   auto issuedCert = id.getKey(keyName).getCertificate(issuedCertName);
   auto issuedCertTlv = issuedCert.wireEncode();
-  auto signature = keyChain.getTpm().sign({{nonce.data(), nonce.size()}}, keyName, DigestAlgorithm::SHA256);
+  auto signature = keyChain.getTpm().sign({{nonce.data(), nonce.size()}}, keyName, ndn::DigestAlgorithm::SHA256);
 
   for (auto& item : params) {
     if (item.first == PARAMETER_KEY_CREDENTIAL_CERT) {
@@ -257,4 +258,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/challenge/challenge-possession.hpp b/src/challenge/challenge-possession.hpp
index 165e20e..ab5e641 100644
--- a/src/challenge/challenge-possession.hpp
+++ b/src/challenge/challenge-possession.hpp
@@ -1,5 +1,5 @@
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -22,7 +22,8 @@
 
 #include "challenge-module.hpp"
 
-namespace ndn {
+#include <ndn-cxx/security/key-chain.hpp>
+
 namespace ndncert {
 
 /**
@@ -66,7 +67,8 @@
 
   static void
   fulfillParameters(std::multimap<std::string, std::string>& params,
-                    KeyChain& keyChain, const Name& issuedCertName, const std::array<uint8_t, 16>& nonce);
+                    ndn::KeyChain& keyChain, const Name& issuedCertName,
+                    const std::array<uint8_t, 16>& nonce);
 
   // challenge parameters
   static const std::string PARAMETER_KEY_CREDENTIAL_CERT;
@@ -79,11 +81,10 @@
   parseConfigFile();
 
 NDNCERT_PUBLIC_WITH_TESTS_ELSE_PRIVATE:
-  std::list<security::Certificate> m_trustAnchors;
+  std::list<Certificate> m_trustAnchors;
   std::string m_configFile;
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_CHALLENGE_POSSESSION_HPP
diff --git a/src/detail/ca-configuration.cpp b/src/detail/ca-configuration.cpp
index 813c428..a6d26a0 100644
--- a/src/detail/ca-configuration.cpp
+++ b/src/detail/ca-configuration.cpp
@@ -25,7 +25,6 @@
 #include <boost/filesystem.hpp>
 #include <boost/property_tree/json_parser.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
@@ -57,7 +56,7 @@
         NDN_THROW(std::runtime_error("Redirect-to item's ca-prefix or certificate cannot be empty."));
       }
       std::istringstream ss(caCertStr);
-      auto caCert = io::load<security::Certificate>(ss);
+      auto caCert = ndn::io::load<Certificate>(ss);
       redirection.push_back(caCert);
     }
   }
@@ -77,4 +76,3 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ca-configuration.hpp b/src/detail/ca-configuration.hpp
index ba3de47..2a2a9ff 100644
--- a/src/detail/ca-configuration.hpp
+++ b/src/detail/ca-configuration.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -24,7 +24,6 @@
 #include "detail/ca-profile.hpp"
 #include "name-assignment/assignment-func.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
@@ -67,7 +66,7 @@
   /**
    * @brief Used for CA redirection
    */
-  std::vector<std::shared_ptr<security::Certificate>> redirection;
+  std::vector<std::shared_ptr<Certificate>> redirection;
   /**
    * @brief Name Assignment Functions
    */
@@ -76,6 +75,5 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CA_CONFIGURATION_HPP
diff --git a/src/detail/ca-memory.cpp b/src/detail/ca-memory.cpp
index 48a0903..eae67cc 100644
--- a/src/detail/ca-memory.cpp
+++ b/src/detail/ca-memory.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,15 +19,11 @@
  */
 
 #include "detail/ca-memory.hpp"
-#include <ndn-cxx/security/validation-policy.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
-const std::string
-CaMemory::STORAGE_TYPE = "ca-storage-memory";
-
+const std::string CaMemory::STORAGE_TYPE = "ca-storage-memory";
 NDNCERT_REGISTER_CA_STORAGE(CaMemory);
 
 CaMemory::CaMemory(const Name& caName, const std::string& path)
@@ -40,7 +36,8 @@
 {
   auto search = m_requests.find(requestId);
   if (search == m_requests.end()) {
-    NDN_THROW(std::runtime_error("Request " + toHex(requestId.data(), requestId.size()) + " doest not exists"));
+    NDN_THROW(std::runtime_error("Request " + ndn::toHex(requestId.data(), requestId.size()) +
+                                 " does not exists"));
   }
   return search->second;
 }
@@ -53,7 +50,8 @@
     m_requests.insert(std::make_pair(request.requestId, request));
   }
   else {
-    NDN_THROW(std::runtime_error("Request " + toHex(request.requestId.data(), request.requestId.size()) + " already exists"));
+    NDN_THROW(std::runtime_error("Request " + ndn::toHex(request.requestId.data(), request.requestId.size()) +
+                                 " already exists"));
   }
 }
 
@@ -103,4 +101,3 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ca-memory.hpp b/src/detail/ca-memory.hpp
index d61fc10..6d8b115 100644
--- a/src/detail/ca-memory.hpp
+++ b/src/detail/ca-memory.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ca-storage.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
@@ -64,6 +63,5 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CA_MEMORY_HPP
diff --git a/src/detail/ca-profile.cpp b/src/detail/ca-profile.cpp
index 0f1ad01..624ec7a 100644
--- a/src/detail/ca-profile.cpp
+++ b/src/detail/ca-profile.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,10 +20,11 @@
 
 #include "detail/ca-profile.hpp"
 #include "challenge/challenge-module.hpp"
+
 #include <ndn-cxx/util/io.hpp>
+
 #include <boost/filesystem.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 CaProfile
@@ -79,7 +80,7 @@
   auto certificateStr = json.get(CONFIG_CERTIFICATE, "");
   if (certificateStr != "") {
     std::istringstream ss(certificateStr);
-    profile.cert = io::load<security::Certificate>(ss);
+    profile.cert = ndn::io::load<Certificate>(ss);
   }
   return profile;
 }
@@ -114,11 +115,10 @@
   }
   if (cert != nullptr) {
     std::stringstream ss;
-    io::save(*cert, ss);
+    ndn::io::save(*cert, ss);
     caItem.put("certificate", ss.str());
   }
   return caItem;
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ca-profile.hpp b/src/detail/ca-profile.hpp
index 69adf43..0592be5 100644
--- a/src/detail/ca-profile.hpp
+++ b/src/detail/ca-profile.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ndncert-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 // used in parsing CA configuration file and Client CA profile storage file
@@ -90,10 +89,9 @@
   /**
    * @brief CA's certificate. Only Client side will have m_cert.
    */
-  std::shared_ptr<security::Certificate> cert;
+  std::shared_ptr<Certificate> cert;
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CA_PROFILE_HPP
diff --git a/src/detail/ca-request-state.cpp b/src/detail/ca-request-state.cpp
index b8a6b27..68d189a 100644
--- a/src/detail/ca-request-state.cpp
+++ b/src/detail/ca-request-state.cpp
@@ -24,7 +24,6 @@
 
 #include <boost/property_tree/json_parser.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 std::string statusToString(Status status)
@@ -72,7 +71,7 @@
 operator<<(std::ostream& os, const RequestState& request)
 {
   os << "Request's CA name: " << request.caPrefix << "\n";
-  os << "Request's request ID: " << toHex(request.requestId.data(), request.requestId.size()) << "\n";
+  os << "Request's request ID: " << ndn::toHex(request.requestId.data(), request.requestId.size()) << "\n";
   os << "Request's status: " << statusToString(request.status) << "\n";
   os << "Request's challenge type: " << request.challengeType << "\n";
   if (request.challengeState) {
@@ -85,11 +84,10 @@
     os << "Challenge secret: " << ss.str() << "\n";
   }
   os << "Certificate:\n";
-  util::IndentedStream os2(os, "  ");
+  ndn::util::IndentedStream os2(os, "  ");
   os2 << request.cert;
   return os;
 }
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ca-request-state.hpp b/src/detail/ca-request-state.hpp
index fe4db23..2c4a1d6 100644
--- a/src/detail/ca-request-state.hpp
+++ b/src/detail/ca-request-state.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -22,9 +22,9 @@
 #define NDNCERT_DETAIL_CA_REQUEST_STATE_HPP
 
 #include "detail/ndncert-common.hpp"
+
 #include <array>
 
-namespace ndn {
 namespace ndncert {
 
 typedef std::array<uint8_t, 8> RequestId;
@@ -107,7 +107,7 @@
   /**
    * @brief The self-signed certificate in the request.
    */
-  security::Certificate cert;
+  Certificate cert;
   /**
    * @brief The encryption key for the requester.
    */
@@ -135,6 +135,5 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CA_REQUEST_STATE_HPP
diff --git a/src/detail/ca-sqlite.cpp b/src/detail/ca-sqlite.cpp
index c247501..45cd84d 100644
--- a/src/detail/ca-sqlite.cpp
+++ b/src/detail/ca-sqlite.cpp
@@ -28,16 +28,15 @@
 #include <boost/filesystem.hpp>
 #include <boost/property_tree/json_parser.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
-using namespace ndn::util;
-const std::string CaSqlite::STORAGE_TYPE = "ca-storage-sqlite3";
+using ndn::util::Sqlite3Statement;
 
+const std::string CaSqlite::STORAGE_TYPE = "ca-storage-sqlite3";
 NDNCERT_REGISTER_CA_STORAGE(CaSqlite);
 
-std::string
+static std::string
 convertJson2String(const JsonSection& json)
 {
   std::stringstream ss;
@@ -45,7 +44,7 @@
   return ss.str();
 }
 
-JsonSection
+static JsonSection
 convertString2Json(const std::string& jsonContent)
 {
   std::istringstream ss(jsonContent);
@@ -54,7 +53,7 @@
   return json;
 }
 
-static const std::string INITIALIZATION = R"_DBTEXT_(
+const std::string INITIALIZATION = R"SQL(
 CREATE TABLE IF NOT EXISTS
   RequestStates(
     id INTEGER PRIMARY KEY,
@@ -75,10 +74,10 @@
   );
 CREATE UNIQUE INDEX IF NOT EXISTS
   RequestStateIdIndex ON RequestStates(request_id);
-)_DBTEXT_";
+)SQL";
 
 CaSqlite::CaSqlite(const Name& caName, const std::string& path)
-    : CaStorage()
+  : CaStorage()
 {
   // Determine the path of sqlite db
   boost::filesystem::path dbDir;
@@ -143,7 +142,7 @@
     state.requestId = requestId;
     state.caPrefix = Name(statement.getBlock(1));
     state.status = static_cast<Status>(statement.getInt(2));
-    state.cert = security::Certificate(statement.getBlock(4));
+    state.cert = Certificate(statement.getBlock(4));
     state.challengeType = statement.getString(5);
     state.requestType = static_cast<RequestType>(statement.getInt(10));
     std::memcpy(state.encryptionKey.data(), statement.getBlob(11), statement.getSize(11));
@@ -158,7 +157,7 @@
     return state;
   }
   else {
-    NDN_THROW(std::runtime_error("Request " + toHex(requestId.data(), requestId.size()) +
+    NDN_THROW(std::runtime_error("Request " + ndn::toHex(requestId.data(), requestId.size()) +
                                  " cannot be fetched from database"));
   }
 }
@@ -189,7 +188,7 @@
     statement.bind(11, request.challengeState->remainingTime.count());
   }
   if (statement.step() != SQLITE_DONE) {
-    NDN_THROW(std::runtime_error("Request " + toHex(request.requestId.data(), request.requestId.size()) +
+    NDN_THROW(std::runtime_error("Request " + ndn::toHex(request.requestId.data(), request.requestId.size()) +
                                  " cannot be added to database"));
   }
 }
@@ -242,7 +241,7 @@
     state.caPrefix = Name(statement.getBlock(2));
     state.status = static_cast<Status>(statement.getInt(3));
     state.challengeType = statement.getString(6);
-    state.cert = security::Certificate(statement.getBlock(5));
+    state.cert = Certificate(statement.getBlock(5));
     state.requestType = static_cast<RequestType>(statement.getInt(11));
     std::memcpy(state.encryptionKey.data(), statement.getBlob(12), statement.getSize(12));
     state.encryptionIv = std::vector<uint8_t>(statement.getBlob(13), statement.getBlob(13) + statement.getSize(13));
@@ -276,7 +275,7 @@
     state.caPrefix = Name(statement.getBlock(2));
     state.status = static_cast<Status>(statement.getInt(3));
     state.challengeType = statement.getString(6);
-    state.cert = security::Certificate(statement.getBlock(5));
+    state.cert = Certificate(statement.getBlock(5));
     state.requestType = static_cast<RequestType>(statement.getInt(11));
     std::memcpy(state.encryptionKey.data(), statement.getBlob(12), statement.getSize(12));
     state.encryptionIv = std::vector<uint8_t>(statement.getBlob(13), statement.getBlob(13) + statement.getSize(13));
@@ -303,4 +302,3 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ca-sqlite.hpp b/src/detail/ca-sqlite.hpp
index 2577a80..969cacf 100644
--- a/src/detail/ca-sqlite.hpp
+++ b/src/detail/ca-sqlite.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -25,7 +25,6 @@
 
 struct sqlite3;
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
@@ -37,7 +36,7 @@
   explicit
   CaSqlite(const Name& caName, const std::string& path = "");
 
-  ~CaSqlite();
+  ~CaSqlite() override;
 
 public:
   /**
@@ -70,6 +69,5 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CA_SQLITE_HPP
diff --git a/src/detail/ca-storage.cpp b/src/detail/ca-storage.cpp
index a377c6c..24fe38f 100644
--- a/src/detail/ca-storage.cpp
+++ b/src/detail/ca-storage.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,11 +20,10 @@
 
 #include "detail/ca-storage.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
-unique_ptr<CaStorage>
+std::unique_ptr<CaStorage>
 CaStorage::createCaStorage(const std::string& caStorageType, const Name& caName, const std::string& path)
 {
   CaStorageFactory& factory = getFactory();
@@ -41,4 +40,3 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ca-storage.hpp b/src/detail/ca-storage.hpp
index 40166cf..0fa7238 100644
--- a/src/detail/ca-storage.hpp
+++ b/src/detail/ca-storage.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,11 +23,10 @@
 
 #include "detail/ca-request-state.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
-class CaStorage : noncopyable
+class CaStorage : boost::noncopyable
 {
 public: // request related
   /**
@@ -66,14 +65,14 @@
     };
   }
 
-  static unique_ptr<CaStorage>
+  static std::unique_ptr<CaStorage>
   createCaStorage(const std::string& caStorageType, const Name& caName, const std::string& path);
 
   virtual
   ~CaStorage() = default;
 
 private:
-  using CaStorageCreateFunc = function<unique_ptr<CaStorage> (const Name&, const std::string&)>;
+  using CaStorageCreateFunc = std::function<std::unique_ptr<CaStorage> (const Name&, const std::string&)>;
   using CaStorageFactory = std::map<std::string, CaStorageCreateFunc>;
 
   static CaStorageFactory&
@@ -86,12 +85,11 @@
 public:                                                          \
   NdnCert ## C ## CaStorageRegistrationClass()                   \
   {                                                              \
-    ::ndn::ndncert::ca::CaStorage::registerCaStorage<C>();       \
+    ::ndncert::ca::CaStorage::registerCaStorage<C>();            \
   }                                                              \
 } g_NdnCert ## C ## CaStorageRegistrationVariable
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CA_STORAGE_HPP
diff --git a/src/detail/challenge-encoder.cpp b/src/detail/challenge-encoder.cpp
index 11a0168..5d9d46b 100644
--- a/src/detail/challenge-encoder.cpp
+++ b/src/detail/challenge-encoder.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,30 +20,30 @@
 
 #include "detail/challenge-encoder.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 Block
 challengetlv::encodeDataContent(ca::RequestState& request, const Name& issuedCertName)
 {
   Block response(tlv::EncryptedPayload);
-  response.push_back(makeNonNegativeIntegerBlock(tlv::Status, static_cast<uint64_t>(request.status)));
+  response.push_back(ndn::makeNonNegativeIntegerBlock(tlv::Status, static_cast<uint64_t>(request.status)));
   if (request.challengeState) {
-    response.push_back(makeStringBlock(tlv::ChallengeStatus, request.challengeState->challengeStatus));
-    response.push_back(makeNonNegativeIntegerBlock(tlv::RemainingTries,
-                                                   request.challengeState->remainingTries));
-    response.push_back(makeNonNegativeIntegerBlock(tlv::RemainingTime,
-                                                   request.challengeState->remainingTime.count()));
+    response.push_back(ndn::makeStringBlock(tlv::ChallengeStatus, request.challengeState->challengeStatus));
+    response.push_back(ndn::makeNonNegativeIntegerBlock(tlv::RemainingTries,
+                                                        request.challengeState->remainingTries));
+    response.push_back(ndn::makeNonNegativeIntegerBlock(tlv::RemainingTime,
+                                                        request.challengeState->remainingTime.count()));
     if (request.challengeState->challengeStatus == "need-proof") {
-      response.push_back(makeStringBlock(tlv::ParameterKey, "nonce"));
-      auto nonce = fromHex(request.challengeState->secrets.get("nonce", ""));
-      response.push_back(makeBinaryBlock(tlv::ParameterValue, nonce->data(), 16));
+      response.push_back(ndn::makeStringBlock(tlv::ParameterKey, "nonce"));
+      auto nonce = ndn::fromHex(request.challengeState->secrets.get("nonce", ""));
+      response.push_back(ndn::makeBinaryBlock(tlv::ParameterValue, nonce->data(), 16));
     }
   }
   if (!issuedCertName.empty()) {
     response.push_back(makeNestedBlock(tlv::IssuedCertName, issuedCertName));
   }
   response.encode();
+
   return encodeBlockWithAesGcm128(ndn::tlv::Content, request.encryptionKey.data(),
                                   response.value(), response.value_size(),
                                   request.requestId.data(), request.requestId.size(),
@@ -56,8 +56,9 @@
   auto result = decodeBlockWithAesGcm128(contentBlock, state.m_aesKey.data(),
                                          state.m_requestId.data(), state.m_requestId.size(),
                                          state.m_decryptionIv, state.m_encryptionIv);
-  auto data = makeBinaryBlock(tlv::EncryptedPayload, result.data(), result.size());
+  auto data = ndn::makeBinaryBlock(tlv::EncryptedPayload, result.data(), result.size());
   data.parse();
+
   state.m_status = statusFromBlock(data.get(tlv::Status));
   if (data.find(tlv::ChallengeStatus) != data.elements_end()) {
     state.m_challengeStatus = readString(data.get(tlv::ChallengeStatus));
@@ -87,4 +88,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/challenge-encoder.hpp b/src/detail/challenge-encoder.hpp
index a8baa57..2013061 100644
--- a/src/detail/challenge-encoder.hpp
+++ b/src/detail/challenge-encoder.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -24,7 +24,6 @@
 #include "detail/ca-request-state.hpp"
 #include "requester-request.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace challengetlv {
 
@@ -36,6 +35,5 @@
 
 } // namespace challengetlv
 } // namespace ndncert
-} // namespace ndn
 
-#endif // NDNCERT_DETAIL_CHALLENGE_ENCODER_HPP
\ No newline at end of file
+#endif // NDNCERT_DETAIL_CHALLENGE_ENCODER_HPP
diff --git a/src/detail/crypto-helpers.cpp b/src/detail/crypto-helpers.cpp
index a2a0af5..d0c2e55 100644
--- a/src/detail/crypto-helpers.cpp
+++ b/src/detail/crypto-helpers.cpp
@@ -37,7 +37,6 @@
 
 #include <cstring>
 
-namespace ndn {
 namespace ndncert {
 
 ECDHState::ECDHState()
@@ -416,25 +415,25 @@
 {
   // The spec of AES encrypted payload TLV used in NDNCERT:
   //   https://github.com/named-data/ndncert/wiki/NDNCERT-Protocol-0.3#242-aes-gcm-encryption
-  Buffer encryptedPayload(payloadSize);
+  ndn::Buffer encryptedPayload(payloadSize);
   uint8_t tag[16];
   if (encryptionIv.empty()) {
     encryptionIv.resize(12, 0);
-    random::generateSecureBytes(encryptionIv.data(), 8);
+    ndn::random::generateSecureBytes(encryptionIv.data(), 8);
   }
   size_t encryptedPayloadLen = aesGcm128Encrypt(payload, payloadSize, associatedData, associatedDataSize,
                                                 key, encryptionIv.data(), encryptedPayload.data(), tag);
   Block content(tlvType);
-  content.push_back(makeBinaryBlock(tlv::InitializationVector, encryptionIv.data(), encryptionIv.size()));
-  content.push_back(makeBinaryBlock(tlv::AuthenticationTag, tag, 16));
-  content.push_back(makeBinaryBlock(tlv::EncryptedPayload, encryptedPayload.data(), encryptedPayloadLen));
+  content.push_back(ndn::makeBinaryBlock(tlv::InitializationVector, encryptionIv.data(), encryptionIv.size()));
+  content.push_back(ndn::makeBinaryBlock(tlv::AuthenticationTag, tag, 16));
+  content.push_back(ndn::makeBinaryBlock(tlv::EncryptedPayload, encryptedPayload.data(), encryptedPayloadLen));
   content.encode();
   // update IV's counter
   updateIv(encryptionIv, payloadSize);
   return content;
 }
 
-Buffer
+ndn::Buffer
 decodeBlockWithAesGcm128(const Block& block, const uint8_t* key,
                          const uint8_t* associatedData, size_t associatedDataSize,
                          std::vector<uint8_t>& decryptionIv, const std::vector<uint8_t>& encryptionIv)
@@ -443,7 +442,7 @@
   //   https://github.com/named-data/ndncert/wiki/NDNCERT-Protocol-0.3#242-aes-gcm-encryption
   block.parse();
   const auto& encryptedPayloadBlock = block.get(tlv::EncryptedPayload);
-  Buffer result(encryptedPayloadBlock.value_size());
+  ndn::Buffer result(encryptedPayloadBlock.value_size());
   if (block.get(tlv::InitializationVector).value_size() != 12 ||
       block.get(tlv::AuthenticationTag).value_size() != 16) {
     NDN_THROW(std::runtime_error("Error when decrypting the AES Encrypted Block: "
@@ -478,4 +477,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/crypto-helpers.hpp b/src/detail/crypto-helpers.hpp
index 9701786..235c6b5 100644
--- a/src/detail/crypto-helpers.hpp
+++ b/src/detail/crypto-helpers.hpp
@@ -25,7 +25,6 @@
 
 #include <openssl/evp.h>
 
-namespace ndn {
 namespace ndncert {
 
 /**
@@ -33,7 +32,7 @@
  *
  * The ECDH is based on prime256v1.
  */
-class ECDHState : noncopyable
+class ECDHState : boost::noncopyable
 {
 public:
   ECDHState();
@@ -169,7 +168,7 @@
  *                     invocations of this function with the same @p key.
  * @return Buffer The plaintext buffer.
  */
-Buffer
+ndn::Buffer
 decodeBlockWithAesGcm128(const Block& block, const uint8_t* key,
                          const uint8_t* associatedData, size_t associatedDataSize,
                          std::vector<uint8_t>& decryptionIv, const std::vector<uint8_t>& encryptionIv);
@@ -183,6 +182,5 @@
 #endif
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_CRYPTO_HELPERS_HPP
diff --git a/src/detail/error-encoder.cpp b/src/detail/error-encoder.cpp
index 3fbbdc2..e1e4357 100644
--- a/src/detail/error-encoder.cpp
+++ b/src/detail/error-encoder.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,15 +20,14 @@
 
 #include "detail/error-encoder.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 Block
 errortlv::encodeDataContent(ErrorCode errorCode, const std::string& description)
 {
   Block response(ndn::tlv::Content);
-  response.push_back(makeNonNegativeIntegerBlock(tlv::ErrorCode, static_cast<size_t>(errorCode)));
-  response.push_back(makeStringBlock(tlv::ErrorInfo, description));
+  response.push_back(ndn::makeNonNegativeIntegerBlock(tlv::ErrorCode, static_cast<size_t>(errorCode)));
+  response.push_back(ndn::makeStringBlock(tlv::ErrorInfo, description));
   response.encode();
   return response;
 }
@@ -45,4 +44,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/error-encoder.hpp b/src/detail/error-encoder.hpp
index 67fe80f..3b17353 100644
--- a/src/detail/error-encoder.hpp
+++ b/src/detail/error-encoder.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ca-profile.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace errortlv {
 
@@ -41,6 +40,5 @@
 
 } // namespace errortlv
 } // namespace ndncert
-} // namespace ndn
 
-#endif // NDNCERT_DETAIL_ERROR_ENCODER_HPP
\ No newline at end of file
+#endif // NDNCERT_DETAIL_ERROR_ENCODER_HPP
diff --git a/src/detail/info-encoder.cpp b/src/detail/info-encoder.cpp
index 79f617f..e6e6581 100644
--- a/src/detail/info-encoder.cpp
+++ b/src/detail/info-encoder.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,11 +20,10 @@
 
 #include "detail/info-encoder.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 Block
-infotlv::encodeDataContent(const CaProfile& caConfig, const security::Certificate& certificate)
+infotlv::encodeDataContent(const CaProfile& caConfig, const Certificate& certificate)
 {
   Block content(ndn::tlv::Content);
   content.push_back(makeNestedBlock(tlv::CaPrefix, caConfig.caPrefix));
@@ -35,11 +34,11 @@
   else {
     caInfo = caConfig.caInfo;
   }
-  content.push_back(makeStringBlock(tlv::CaInfo, caInfo));
+  content.push_back(ndn::makeStringBlock(tlv::CaInfo, caInfo));
   for (const auto& key : caConfig.probeParameterKeys) {
-    content.push_back(makeStringBlock(tlv::ParameterKey, key));
+    content.push_back(ndn::makeStringBlock(tlv::ParameterKey, key));
   }
-  content.push_back(makeNonNegativeIntegerBlock(tlv::MaxValidityPeriod, caConfig.maxValidityPeriod.count()));
+  content.push_back(ndn::makeNonNegativeIntegerBlock(tlv::MaxValidityPeriod, caConfig.maxValidityPeriod.count()));
   content.push_back(makeNestedBlock(tlv::CaCertificate, certificate));
   content.encode();
   return content;
@@ -67,7 +66,7 @@
       break;
     case tlv::CaCertificate:
       item.parse();
-      result.cert = std::make_shared<security::Certificate>(item.get(ndn::tlv::Data));
+      result.cert = std::make_shared<Certificate>(item.get(ndn::tlv::Data));
       break;
     default:
       continue;
@@ -78,4 +77,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
\ No newline at end of file
diff --git a/src/detail/info-encoder.hpp b/src/detail/info-encoder.hpp
index 7f9180e..4eaa967 100644
--- a/src/detail/info-encoder.hpp
+++ b/src/detail/info-encoder.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ca-profile.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace infotlv {
 
@@ -31,7 +30,7 @@
  * Encode CA configuration and its certificate into a TLV block as INFO Data packet content.
  */
 Block
-encodeDataContent(const CaProfile& caConfig, const security::Certificate& certificate);
+encodeDataContent(const CaProfile& caConfig, const Certificate& certificate);
 
 /**
  * Decode CA configuration from the TLV block of INFO Data packet content.
@@ -41,6 +40,5 @@
 
 } // namespace infotlv
 } // namespace ndncert
-} // namespace ndn
 
-#endif // NDNCERT_DETAIL_INFO_ENCODER_HPP
\ No newline at end of file
+#endif // NDNCERT_DETAIL_INFO_ENCODER_HPP
diff --git a/src/detail/ndncert-common.cpp b/src/detail/ndncert-common.cpp
index 7c210b7..5e22afb 100644
--- a/src/detail/ndncert-common.cpp
+++ b/src/detail/ndncert-common.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,7 +20,6 @@
 
 #include "detail/ndncert-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 std::ostream&
@@ -56,4 +55,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/ndncert-common.hpp b/src/detail/ndncert-common.hpp
index 01fa883..d9863a5 100644
--- a/src/detail/ndncert-common.hpp
+++ b/src/detail/ndncert-common.hpp
@@ -41,26 +41,37 @@
 #include <tuple>
 
 #include <ndn-cxx/data.hpp>
-#include <ndn-cxx/encoding/block-helpers.hpp>
 #include <ndn-cxx/encoding/block.hpp>
-#include <ndn-cxx/encoding/tlv.hpp>
-#include <ndn-cxx/face.hpp>
+#include <ndn-cxx/encoding/block-helpers.hpp>
 #include <ndn-cxx/interest.hpp>
-#include <ndn-cxx/lp/nack.hpp>
 #include <ndn-cxx/name.hpp>
 #include <ndn-cxx/security/certificate.hpp>
-#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/util/exception.hpp>
 #include <ndn-cxx/util/logger.hpp>
 #include <ndn-cxx/util/optional.hpp>
+#include <ndn-cxx/util/time.hpp>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/assert.hpp>
 #include <boost/noncopyable.hpp>
 #include <boost/property_tree/ptree.hpp>
 
-namespace ndn {
 namespace ndncert {
 
+using ndn::Block;
+using ndn::Data;
+using ndn::Interest;
+using ndn::Name;
+using ndn::SignatureInfo;
+using ndn::security::Certificate;
+
+using ndn::optional;
+using ndn::nullopt;
+
+namespace time = ndn::time;
+using namespace ndn::time_literals;
+using namespace std::string_literals;
+
 namespace tlv {
 
 enum : uint32_t {
@@ -127,6 +138,5 @@
 operator<<(std::ostream& out, RequestType type);
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_NDNCERT_COMMON_HPP
diff --git a/src/detail/probe-encoder.cpp b/src/detail/probe-encoder.cpp
index 24471a7..bf51438 100644
--- a/src/detail/probe-encoder.cpp
+++ b/src/detail/probe-encoder.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,7 +20,6 @@
 
 #include "detail/probe-encoder.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 Block
@@ -28,8 +27,8 @@
 {
   Block content(ndn::tlv::ApplicationParameters);
   for (const auto& items : parameters) {
-    content.push_back(makeStringBlock(tlv::ParameterKey, items.first));
-    content.push_back(makeStringBlock(tlv::ParameterValue, items.second));
+    content.push_back(ndn::makeStringBlock(tlv::ParameterKey, items.first));
+    content.push_back(ndn::makeStringBlock(tlv::ParameterValue, items.second));
   }
   content.encode();
   return content;
@@ -51,14 +50,14 @@
 
 Block
 probetlv::encodeDataContent(const std::vector<Name>& identifiers, optional<size_t> maxSuffixLength,
-                                std::vector<std::shared_ptr<security::Certificate>> redirectionItems)
+                            std::vector<std::shared_ptr<Certificate>> redirectionItems)
 {
   Block content(ndn::tlv::Content);
   for (const auto& name : identifiers) {
     Block item(tlv::ProbeResponse);
     item.push_back(name.wireEncode());
     if (maxSuffixLength) {
-      item.push_back(makeNonNegativeIntegerBlock(tlv::MaxSuffixLength, *maxSuffixLength));
+      item.push_back(ndn::makeNonNegativeIntegerBlock(tlv::MaxSuffixLength, *maxSuffixLength));
     }
     content.push_back(item);
   }
@@ -71,8 +70,8 @@
 
 void
 probetlv::decodeDataContent(const Block& block,
-                                std::vector<std::pair<Name, int>>& availableNames,
-                                std::vector<Name>& availableRedirection)
+                            std::vector<std::pair<Name, int>>& availableNames,
+                            std::vector<Name>& availableRedirection)
 {
   block.parse();
   for (const auto& item : block.elements()) {
@@ -103,4 +102,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
\ No newline at end of file
diff --git a/src/detail/probe-encoder.hpp b/src/detail/probe-encoder.hpp
index 58bcb44..6afe083 100644
--- a/src/detail/probe-encoder.hpp
+++ b/src/detail/probe-encoder.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ndncert-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace probetlv {
 
@@ -39,14 +38,13 @@
 Block
 encodeDataContent(const std::vector<Name>& identifiers,
                   optional<size_t> maxSuffixLength = nullopt,
-                  std::vector<std::shared_ptr<security::Certificate>> redirectionItems =
-                          std::vector<std::shared_ptr<security::Certificate>>());
+                  std::vector<std::shared_ptr<Certificate>> redirectionItems =
+                          std::vector<std::shared_ptr<Certificate>>());
 
 std::multimap<std::string, std::string>
 decodeApplicationParameters(const Block& block);
 
 } // namespace probetlv
 } // namespace ndncert
-} // namespace ndn
 
-#endif // NDNCERT_DETAIL_PROBE_ENCODER_HPP
\ No newline at end of file
+#endif // NDNCERT_DETAIL_PROBE_ENCODER_HPP
diff --git a/src/detail/profile-storage.cpp b/src/detail/profile-storage.cpp
index 949309a..8ae2bb6 100644
--- a/src/detail/profile-storage.cpp
+++ b/src/detail/profile-storage.cpp
@@ -23,7 +23,6 @@
 #include <boost/filesystem.hpp>
 #include <boost/property_tree/json_parser.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace requester {
 
@@ -99,4 +98,3 @@
 
 } // namespace requester
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/detail/profile-storage.hpp b/src/detail/profile-storage.hpp
index 5955f15..3df6407 100644
--- a/src/detail/profile-storage.hpp
+++ b/src/detail/profile-storage.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ca-profile.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace requester {
 
@@ -69,6 +68,5 @@
 
 } // namespace requester
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_PROFILE_STORAGE_HPP
diff --git a/src/detail/request-encoder.cpp b/src/detail/request-encoder.cpp
index 1801b63..30e2523 100644
--- a/src/detail/request-encoder.cpp
+++ b/src/detail/request-encoder.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,20 +19,21 @@
  */
 
 #include "detail/request-encoder.hpp"
+
 #include <ndn-cxx/security/transform/base64-encode.hpp>
 #include <ndn-cxx/security/transform/buffer-source.hpp>
 #include <ndn-cxx/security/transform/stream-sink.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 Block
-requesttlv::encodeApplicationParameters(RequestType requestType, const std::vector <uint8_t>& ecdhPub,
-                                        const security::Certificate& certRequest)
+requesttlv::encodeApplicationParameters(RequestType requestType,
+                                        const std::vector<uint8_t>& ecdhPub,
+                                        const Certificate& certRequest)
 {
   Block
   request(ndn::tlv::ApplicationParameters);
-  request.push_back(makeBinaryBlock(tlv::EcdhPub, ecdhPub.data(), ecdhPub.size()));
+  request.push_back(ndn::makeBinaryBlock(tlv::EcdhPub, ecdhPub.data(), ecdhPub.size()));
   if (requestType == RequestType::NEW || requestType == RequestType::RENEW) {
     request.push_back(makeNestedBlock(tlv::CertRequest, certRequest));
   }
@@ -45,8 +46,8 @@
 
 void
 requesttlv::decodeApplicationParameters(const Block& payload, RequestType requestType,
-                                        std::vector <uint8_t>& ecdhPub,
-                                        shared_ptr <security::Certificate>& clientCert)
+                                        std::vector<uint8_t>& ecdhPub,
+                                        std::shared_ptr<Certificate>& clientCert)
 {
   payload.parse();
 
@@ -63,8 +64,7 @@
   }
   requestPayload.parse();
 
-  security::Certificate cert = security::Certificate(requestPayload.get(ndn::tlv::Data));
-  clientCert = std::make_shared<security::Certificate>(cert);
+  clientCert = std::make_shared<Certificate>(requestPayload.get(ndn::tlv::Data));
 }
 
 Block
@@ -73,11 +73,11 @@
                               const std::vector <std::string>& challenges)
 {
   Block response(ndn::tlv::Content);
-  response.push_back(makeBinaryBlock(tlv::EcdhPub, ecdhKey.data(), ecdhKey.size()));
-  response.push_back(makeBinaryBlock(tlv::Salt, salt.data(), salt.size()));
-  response.push_back(makeBinaryBlock(tlv::RequestId, requestId.data(), requestId.size()));
+  response.push_back(ndn::makeBinaryBlock(tlv::EcdhPub, ecdhKey.data(), ecdhKey.size()));
+  response.push_back(ndn::makeBinaryBlock(tlv::Salt, salt.data(), salt.size()));
+  response.push_back(ndn::makeBinaryBlock(tlv::RequestId, requestId.data(), requestId.size()));
   for (const auto& entry: challenges) {
-    response.push_back(makeStringBlock(tlv::Challenge, entry));
+    response.push_back(ndn::makeStringBlock(tlv::Challenge, entry));
   }
   response.encode();
   return response;
@@ -109,4 +109,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
\ No newline at end of file
diff --git a/src/detail/request-encoder.hpp b/src/detail/request-encoder.hpp
index aff7c62..e94571e 100644
--- a/src/detail/request-encoder.hpp
+++ b/src/detail/request-encoder.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,17 +23,16 @@
 
 #include "detail/ca-request-state.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace requesttlv {
 
 Block
 encodeApplicationParameters(RequestType requestType, const std::vector<uint8_t>& ecdhPub,
-                            const security::Certificate& certRequest);
+                            const Certificate& certRequest);
 
 void
 decodeApplicationParameters(const Block& block, RequestType requestType, std::vector<uint8_t>& ecdhPub,
-                            shared_ptr<security::Certificate>& certRequest);
+                            std::shared_ptr<Certificate>& certRequest);
 
 Block
 encodeDataContent(const std::vector<uint8_t>& ecdhKey, const std::array<uint8_t, 32>& salt,
@@ -45,6 +44,5 @@
 
 } // namespace requesttlv
 } // namespace ndncert
-} // namespace ndn
 
-#endif // NDNCERT_DETAIL_NEW_RENEW_REVOKE_ENCODER_HPP
\ No newline at end of file
+#endif // NDNCERT_DETAIL_REQUEST_ENCODER_HPP
diff --git a/src/name-assignment/assignment-func.cpp b/src/name-assignment/assignment-func.cpp
index d65eefd..f4728d3 100644
--- a/src/name-assignment/assignment-func.cpp
+++ b/src/name-assignment/assignment-func.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,9 +19,7 @@
  */
 
 #include "assignment-func.hpp"
-#include <ndn-cxx/util/random.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 NameAssignmentFunc::NameAssignmentFunc(const std::string& format)
@@ -39,7 +37,7 @@
   }
 }
 
-unique_ptr<NameAssignmentFunc>
+std::unique_ptr<NameAssignmentFunc>
 NameAssignmentFunc::createNameAssignmentFunc(const std::string& challengeType, const std::string& format)
 {
   CurriedFuncFactory& factory = getFactory();
@@ -55,4 +53,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/name-assignment/assignment-func.hpp b/src/name-assignment/assignment-func.hpp
index 9e9b128..7f35fcf 100644
--- a/src/name-assignment/assignment-func.hpp
+++ b/src/name-assignment/assignment-func.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -22,12 +22,12 @@
 #define NDNCERT_ASSIGNMENT_FUNC_HPP
 
 #include "detail/ca-request-state.hpp"
+
 #include <map>
 
-namespace ndn {
 namespace ndncert {
 
-class NameAssignmentFunc : noncopyable
+class NameAssignmentFunc : boost::noncopyable
 {
 protected:
   explicit NameAssignmentFunc(const std::string& format = "");
@@ -45,7 +45,7 @@
    * @param vector A list of parameter key-value pair used for name assignment.
    * @return a vector containing the possible namespaces derived from the parameters.
    */
-  virtual std::vector<PartialName>
+  virtual std::vector<ndn::PartialName>
   assignName(const std::multimap<std::string, std::string>& params) = 0;
 
 public:
@@ -58,14 +58,14 @@
     factory[typeName] = [](const std::string& format) { return std::make_unique<AssignmentType>(format); };
   }
 
-  static unique_ptr<NameAssignmentFunc>
+  static std::unique_ptr<NameAssignmentFunc>
   createNameAssignmentFunc(const std::string& challengeType, const std::string& format = "");
 
 NDNCERT_PUBLIC_WITH_TESTS_ELSE_PROTECTED:
   std::vector<std::string> m_nameFormat;
 
 private:
-  typedef function<unique_ptr<NameAssignmentFunc>(const std::string&)> FactoryCreateFunc;
+  typedef std::function<std::unique_ptr<NameAssignmentFunc>(const std::string&)> FactoryCreateFunc;
   typedef std::map<std::string, FactoryCreateFunc> CurriedFuncFactory;
 
   static CurriedFuncFactory&
@@ -73,15 +73,15 @@
 };
 
 #define NDNCERT_REGISTER_FUNCFACTORY(C, T)                                        \
-  static class NdnCert##C##FuncFactoryRegistrationClass {                         \
+  static class NdnCert##C##FuncFactoryRegistrationClass                           \
+  {                                                                               \
   public:                                                                         \
     NdnCert##C##FuncFactoryRegistrationClass()                                    \
     {                                                                             \
-      ::ndn::ndncert::NameAssignmentFunc::registerNameAssignmentFunc<C>(T);       \
+      ::ndncert::NameAssignmentFunc::registerNameAssignmentFunc<C>(T);            \
     }                                                                             \
   } g_NdnCert##C##ChallengeRegistrationVariable
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_ASSIGNMENT_FUNC_HPP
diff --git a/src/name-assignment/assignment-hash.cpp b/src/name-assignment/assignment-hash.cpp
index f292821..f406619 100644
--- a/src/name-assignment/assignment-hash.cpp
+++ b/src/name-assignment/assignment-hash.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,26 +19,27 @@
  */
 
 #include "assignment-hash.hpp"
+
 #include <ndn-cxx/util/sha256.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 NDNCERT_REGISTER_FUNCFACTORY(AssignmentHash, "hash");
 
 AssignmentHash::AssignmentHash(const std::string& format)
   : NameAssignmentFunc(format)
-{}
+{
+}
 
-std::vector<PartialName>
+std::vector<ndn::PartialName>
 AssignmentHash::assignName(const std::multimap<std::string, std::string>& params)
 {
-  std::vector<PartialName> resultList;
+  std::vector<ndn::PartialName> resultList;
   Name result;
   for (const auto& item : m_nameFormat) {
     auto it = params.find(item);
     if (it != params.end()) {
-      util::Sha256 digest;
+      ndn::util::Sha256 digest;
       digest << it->second;
       result.append(digest.toString());
     }
@@ -51,4 +52,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/name-assignment/assignment-hash.hpp b/src/name-assignment/assignment-hash.hpp
index 83acc28..66d3984 100644
--- a/src/name-assignment/assignment-hash.hpp
+++ b/src/name-assignment/assignment-hash.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "assignment-func.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 /**
@@ -34,12 +33,10 @@
 public:
   AssignmentHash(const std::string& format = "");
 
-  std::vector<PartialName>
+  std::vector<ndn::PartialName>
   assignName(const std::multimap<std::string, std::string>& params) override;
-
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_ASSIGNMENT_HASH_HPP
diff --git a/src/name-assignment/assignment-param.cpp b/src/name-assignment/assignment-param.cpp
index 53022cc..956b3d8 100644
--- a/src/name-assignment/assignment-param.cpp
+++ b/src/name-assignment/assignment-param.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,19 +20,19 @@
 
 #include "assignment-param.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 NDNCERT_REGISTER_FUNCFACTORY(AssignmentParam, "param");
 
 AssignmentParam::AssignmentParam(const std::string& format)
   : NameAssignmentFunc(format)
-{}
+{
+}
 
-std::vector<PartialName>
+std::vector<ndn::PartialName>
 AssignmentParam::assignName(const std::multimap<std::string, std::string>& params)
 {
-  std::vector<PartialName> resultList;
+  std::vector<ndn::PartialName> resultList;
   Name result;
   for (const auto& item : m_nameFormat) {
     auto it = std::find_if(params.begin(), params.end(),
@@ -49,4 +49,3 @@
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/name-assignment/assignment-param.hpp b/src/name-assignment/assignment-param.hpp
index 52bcb80..fc77d27 100644
--- a/src/name-assignment/assignment-param.hpp
+++ b/src/name-assignment/assignment-param.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "assignment-func.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 /**
@@ -34,12 +33,10 @@
 public:
   AssignmentParam(const std::string& format = "");
 
-  std::vector<PartialName>
+  std::vector<ndn::PartialName>
   assignName(const std::multimap<std::string, std::string>& params) override;
-
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_ASSIGNMENT_PARAM_HPP
diff --git a/src/name-assignment/assignment-random.cpp b/src/name-assignment/assignment-random.cpp
index 284a1f7..3305cae 100644
--- a/src/name-assignment/assignment-random.cpp
+++ b/src/name-assignment/assignment-random.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,24 +19,22 @@
  */
 
 #include "assignment-random.hpp"
+
 #include <ndn-cxx/util/random.hpp>
 
-namespace ndn {
 namespace ndncert {
 
 NDNCERT_REGISTER_FUNCFACTORY(AssignmentRandom, "random");
 
 AssignmentRandom::AssignmentRandom(const std::string& format)
   : NameAssignmentFunc(format)
-{}
-
-std::vector<PartialName>
-AssignmentRandom::assignName(const std::multimap<std::string, std::string>& params)
 {
-  std::vector<PartialName> resultList;
-  resultList.emplace_back(to_string(random::generateSecureWord64()));
-  return resultList;
+}
+
+std::vector<ndn::PartialName>
+AssignmentRandom::assignName(const std::multimap<std::string, std::string>&)
+{
+  return {ndn::PartialName(ndn::to_string(ndn::random::generateSecureWord64()))};
 }
 
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/name-assignment/assignment-random.hpp b/src/name-assignment/assignment-random.hpp
index 86f8096..872c784 100644
--- a/src/name-assignment/assignment-random.hpp
+++ b/src/name-assignment/assignment-random.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "assignment-func.hpp"
 
-namespace ndn {
 namespace ndncert {
 
 /**
@@ -34,11 +33,10 @@
 public:
   AssignmentRandom(const std::string& format = "");
 
-  std::vector<PartialName>
+  std::vector<ndn::PartialName>
   assignName(const std::multimap<std::string, std::string>& params) override;
 };
 
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_ASSIGNMENT_RANDOM_HPP
diff --git a/src/requester-request.cpp b/src/requester-request.cpp
index 5929794..6ab56ea 100644
--- a/src/requester-request.cpp
+++ b/src/requester-request.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,6 +19,7 @@
  */
 
 #include "requester-request.hpp"
+
 #include "challenge/challenge-module.hpp"
 #include "detail/crypto-helpers.hpp"
 #include "detail/challenge-encoder.hpp"
@@ -26,6 +27,8 @@
 #include "detail/info-encoder.hpp"
 #include "detail/request-encoder.hpp"
 #include "detail/probe-encoder.hpp"
+
+#include <ndn-cxx/metadata-object.hpp>
 #include <ndn-cxx/security/signing-helpers.hpp>
 #include <ndn-cxx/security/transform/base64-encode.hpp>
 #include <ndn-cxx/security/transform/buffer-source.hpp>
@@ -33,41 +36,32 @@
 #include <ndn-cxx/security/verification-helpers.hpp>
 #include <ndn-cxx/util/io.hpp>
 #include <ndn-cxx/util/random.hpp>
-#include <ndn-cxx/metadata-object.hpp>
+
 #include <boost/lexical_cast.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace requester {
 
 NDN_LOG_INIT(ndncert.client);
 
-shared_ptr<Interest>
+std::shared_ptr<Interest>
 Request::genCaProfileDiscoveryInterest(const Name& caName)
 {
   Name contentName = caName;
   if (readString(caName.at(-1)) != "CA")
     contentName.append("CA");
   contentName.append("INFO");
-  return std::make_shared<Interest>(MetadataObject::makeDiscoveryInterest(contentName));
+  return std::make_shared<Interest>(ndn::MetadataObject::makeDiscoveryInterest(contentName));
 }
 
-shared_ptr<Interest>
+std::shared_ptr<Interest>
 Request::genCaProfileInterestFromDiscoveryResponse(const Data& reply)
 {
-  // set naming convention to be typed
-  auto convention = name::getConventionEncoding();
-  name::setConventionEncoding(name::Convention::TYPED);
-
-  auto metaData = MetadataObject(reply);
+  auto metaData = ndn::MetadataObject(reply);
   auto interestName= metaData.getVersionedName();
   interestName.appendSegment(0);
   auto interest = std::make_shared<Interest>(interestName);
   interest->setCanBePrefix(false);
-
-  // set back the convention
-  name::setConventionEncoding(convention);
-
   return interest;
 }
 
@@ -75,7 +69,7 @@
 Request::onCaProfileResponse(const Data& reply)
 {
   auto caItem = infotlv::decodeDataContent(reply.getContent());
-  if (!security::verifySignature(reply, *caItem.cert)) {
+  if (!ndn::security::verifySignature(reply, *caItem.cert)) {
     NDN_LOG_ERROR("Cannot verify replied Data packet signature.");
     NDN_THROW(std::runtime_error("Cannot verify replied Data packet signature."));
   }
@@ -87,7 +81,7 @@
 {
   auto caItem = infotlv::decodeDataContent(reply.getContent());
   auto certBlock = caItem.cert->wireEncode();
-  caItem.cert = std::make_shared<security::Certificate>(certBlock);
+  caItem.cert = std::make_shared<Certificate>(certBlock);
   if (caItem.cert->getFullName() != caCertFullName) {
     NDN_LOG_ERROR("Ca profile does not match the certificate information offered by the original CA.");
     NDN_THROW(std::runtime_error("Cannot verify replied Data packet signature."));
@@ -95,12 +89,12 @@
   return onCaProfileResponse(reply);
 }
 
-shared_ptr<Interest>
+std::shared_ptr<Interest>
 Request::genProbeInterest(const CaProfile& ca, std::multimap<std::string, std::string>&& probeInfo)
 {
   Name interestName = ca.caPrefix;
   interestName.append("CA").append("PROBE");
-  auto interest =std::make_shared<Interest>(interestName);
+  auto interest = std::make_shared<Interest>(interestName);
   interest->setMustBeFresh(true);
   interest->setCanBePrefix(false);
   interest->setApplicationParameters(probetlv::encodeApplicationParameters(std::move(probeInfo)));
@@ -111,7 +105,7 @@
 Request::onProbeResponse(const Data& reply, const CaProfile& ca,
                          std::vector<std::pair<Name, int>>& identityNames, std::vector<Name>& otherCas)
 {
-  if (!security::verifySignature(reply, *ca.cert)) {
+  if (!ndn::security::verifySignature(reply, *ca.cert)) {
     NDN_LOG_ERROR("Cannot verify replied Data packet signature.");
     NDN_THROW(std::runtime_error("Cannot verify replied Data packet signature."));
     return;
@@ -120,13 +114,14 @@
   probetlv::decodeDataContent(reply.getContent(), identityNames, otherCas);
 }
 
-Request::Request(security::KeyChain& keyChain, const CaProfile& profile, RequestType requestType)
-    : m_caProfile(profile)
-    , m_type(requestType)
-    , m_keyChain(keyChain)
-{}
+Request::Request(ndn::KeyChain& keyChain, const CaProfile& profile, RequestType requestType)
+  : m_caProfile(profile)
+  , m_type(requestType)
+  , m_keyChain(keyChain)
+{
+}
 
-shared_ptr<Interest>
+std::shared_ptr<Interest>
 Request::genNewInterest(const Name& newIdentityName,
                         const time::system_clock::TimePoint& notBefore,
                         const time::system_clock::TimePoint& notAfter)
@@ -137,7 +132,7 @@
   if (newIdentityName.empty()) {
     NDN_LOG_TRACE("Randomly create a new name because newIdentityName is empty and the param is empty.");
     m_identityName = m_caProfile.caPrefix;
-    m_identityName.append(std::to_string(random::generateSecureWord64()));
+    m_identityName.append(ndn::to_string(ndn::random::generateSecureWord64()));
   }
   else {
     m_identityName = newIdentityName;
@@ -145,11 +140,11 @@
 
   // generate a newly key pair or use an existing key
   const auto& pib = m_keyChain.getPib();
-  security::pib::Identity identity;
+  ndn::security::pib::Identity identity;
   try {
     identity = pib.getIdentity(m_identityName);
   }
-  catch (const security::Pib::Error& e) {
+  catch (const ndn::security::Pib::Error&) {
     identity = m_keyChain.createIdentity(m_identityName);
     m_isNewlyCreatedIdentity = true;
     m_isNewlyCreatedKey = true;
@@ -157,19 +152,19 @@
   try {
     m_keyPair = identity.getDefaultKey();
   }
-  catch (const security::Pib::Error& e) {
+  catch (const ndn::security::Pib::Error&) {
     m_keyPair = m_keyChain.createKey(identity);
     m_isNewlyCreatedKey = true;
   }
   auto& keyName = m_keyPair.getName();
 
   // generate certificate request
-  security::Certificate certRequest;
+  Certificate certRequest;
   certRequest.setName(Name(keyName).append("cert-request").appendVersion());
   certRequest.setContentType(ndn::tlv::ContentType_Key);
   certRequest.setContent(m_keyPair.getPublicKey().data(), m_keyPair.getPublicKey().size());
   SignatureInfo signatureInfo;
-  signatureInfo.setValidityPeriod(security::ValidityPeriod(notBefore, notAfter));
+  signatureInfo.setValidityPeriod(ndn::security::ValidityPeriod(notBefore, notAfter));
   m_keyChain.sign(certRequest, signingByKey(keyName).setSignatureInfo(signatureInfo));
 
   // generate Interest packet
@@ -186,8 +181,8 @@
   return interest;
 }
 
-shared_ptr<Interest>
-Request::genRevokeInterest(const security::Certificate& certificate)
+std::shared_ptr<Interest>
+Request::genRevokeInterest(const Certificate& certificate)
 {
   if (!m_caProfile.caPrefix.isPrefixOf(certificate.getName())) {
     return nullptr;
@@ -206,7 +201,7 @@
 std::list<std::string>
 Request::onNewRenewRevokeResponse(const Data& reply)
 {
-  if (!security::verifySignature(reply, *m_caProfile.cert)) {
+  if (!ndn::security::verifySignature(reply, *m_caProfile.cert)) {
     NDN_LOG_ERROR("Cannot verify replied Data packet signature.");
     NDN_THROW(std::runtime_error("Cannot verify replied Data packet signature."));
   }
@@ -238,7 +233,7 @@
   return challenge->getRequestedParameterList(m_status, m_challengeStatus);
 }
 
-shared_ptr<Interest>
+std::shared_ptr<Interest>
 Request::genChallengeInterest(std::multimap<std::string, std::string>&& parameters)
 {
   if (m_challengeType == "") {
@@ -269,7 +264,7 @@
 void
 Request::onChallengeResponse(const Data& reply)
 {
-  if (!security::verifySignature(reply, *m_caProfile.cert)) {
+  if (!ndn::security::verifySignature(reply, *m_caProfile.cert)) {
     NDN_LOG_ERROR("Cannot verify replied Data packet signature.");
     NDN_THROW(std::runtime_error("Cannot verify replied Data packet signature."));
   }
@@ -277,23 +272,23 @@
   challengetlv::decodeDataContent(reply.getContent(), *this);
 }
 
-shared_ptr<Interest>
+std::shared_ptr<Interest>
 Request::genCertFetchInterest() const
 {
   Name interestName = m_issuedCertName;
-  auto interest =std::make_shared<Interest>(interestName);
+  auto interest = std::make_shared<Interest>(interestName);
   interest->setMustBeFresh(false);
   interest->setCanBePrefix(false);
   return interest;
 }
 
-shared_ptr<security::Certificate>
+std::shared_ptr<Certificate>
 Request::onCertFetchResponse(const Data& reply)
 {
   try {
-    return std::make_shared<security::Certificate>(reply);
+    return std::make_shared<Certificate>(reply);
   }
-  catch (const std::exception& e) {
+  catch (const std::exception&) {
     NDN_LOG_ERROR("Cannot parse replied certificate ");
     NDN_THROW(std::runtime_error("Cannot parse replied certificate "));
     return nullptr;
@@ -334,4 +329,3 @@
 
 } // namespace requester
 } // namespace ndncert
-} // namespace ndn
diff --git a/src/requester-request.hpp b/src/requester-request.hpp
index a1817ea..acd06cc 100644
--- a/src/requester-request.hpp
+++ b/src/requester-request.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -25,11 +25,12 @@
 #include "detail/crypto-helpers.hpp"
 #include "detail/profile-storage.hpp"
 
-namespace ndn {
+#include <ndn-cxx/security/key-chain.hpp>
+
 namespace ndncert {
 namespace requester {
 
-class Request : noncopyable
+class Request : boost::noncopyable
 {
 public:
   /**
@@ -38,7 +39,7 @@
    * @param caName The name prefix of the CA.
    * @return A shared pointer to an Interest ready to be sent.
    */
-  static shared_ptr<Interest>
+  static std::shared_ptr<Interest>
   genCaProfileDiscoveryInterest(const Name& caName);
 
   /**
@@ -47,7 +48,7 @@
    * @param reply The Data packet replied from discovery Interest.
    * @return A shared pointer to an Interest ready to be sent.
    */
-  static shared_ptr<Interest>
+  static std::shared_ptr<Interest>
   genCaProfileInterestFromDiscoveryResponse(const Data& reply);
 
   /**
@@ -85,7 +86,7 @@
    * @param probeInfo The requester information to carry to the CA
    * @return A shared pointer of to the encoded interest, ready to be sent.
    */
-  static shared_ptr<Interest>
+  static std::shared_ptr<Interest>
   genProbeInterest(const CaProfile& ca, std::multimap<std::string, std::string>&& probeInfo);
 
   /**
@@ -103,9 +104,8 @@
   onProbeResponse(const Data& reply, const CaProfile& ca,
                   std::vector<std::pair<Name, int>>& identityNames, std::vector<Name>& otherCas);
 
-
   explicit
-  Request(security::KeyChain& keyChain, const CaProfile& profile, RequestType requestType);
+  Request(ndn::KeyChain& keyChain, const CaProfile& profile, RequestType requestType);
 
   // NEW/REVOKE/RENEW related helpers
   /**
@@ -117,7 +117,7 @@
    * @param notAfter The expected notAfter field for the certificate (expiration time)
    * @return The shared pointer to the encoded interest.
    */
-  shared_ptr<Interest>
+  std::shared_ptr<Interest>
   genNewInterest(const Name& newIdentityName,
                  const time::system_clock::TimePoint& notBefore,
                  const time::system_clock::TimePoint& notAfter);
@@ -129,8 +129,8 @@
    * @param certificate The certificate to the revoked.
    * @return The shared pointer to the encoded interest.
    */
-  shared_ptr<Interest>
-  genRevokeInterest(const security::Certificate& certificate);
+  std::shared_ptr<Interest>
+  genRevokeInterest(const Certificate& certificate);
 
   /**
    * @brief Decodes the replied data of NEW, RENEW, or REVOKE interest from the CA.
@@ -164,7 +164,7 @@
    * @return The shared pointer to the encoded interest
    * @throw std::runtime_error if the challenge is not selected or is not supported.
    */
-  shared_ptr<Interest>
+  std::shared_ptr<Interest>
   genChallengeInterest(std::multimap<std::string, std::string>&& parameters);
 
   /**
@@ -183,7 +183,7 @@
    * @param state, the state of the request.
    * @return The shared pointer to the encoded interest
    */
-  shared_ptr<Interest>
+  std::shared_ptr<Interest>
   genCertFetchInterest() const;
 
   /**
@@ -192,7 +192,7 @@
    * @param reply, the data replied from the certificate fetch interest.
    * @return The shared pointer to the certificate being fetched.
    */
-  static shared_ptr<security::Certificate>
+  static std::shared_ptr<Certificate>
   onCertFetchResponse(const Data& reply);
 
   /**
@@ -273,7 +273,7 @@
   /**
    * @brief The local keychain to generate and install identities, keys and certificates
    */
-  security::KeyChain& m_keyChain;
+  ndn::KeyChain& m_keyChain;
   /**
    * @brief State about how identity/key is generated.
    */
@@ -282,11 +282,10 @@
   /**
    * @brief The keypair for the request.
    */
-  security::Key m_keyPair;
+  ndn::security::Key m_keyPair;
 };
 
 } // namespace requester
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_REQUESTER_REQUEST_HPP
diff --git a/tests/database-fixture.hpp b/tests/database-fixture.hpp
index 598e304..53f813e 100644
--- a/tests/database-fixture.hpp
+++ b/tests/database-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -24,9 +24,9 @@
 
 #include "identity-management-fixture.hpp"
 #include "unit-test-time-fixture.hpp"
+
 #include <boost/filesystem.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -58,6 +58,5 @@
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_TESTS_DATABASE_FIXTURE_HPP
diff --git a/tests/global-configuration.cpp b/tests/global-configuration.cpp
index 61d0cbd..0c92646 100644
--- a/tests/global-configuration.cpp
+++ b/tests/global-configuration.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -18,12 +18,14 @@
  * See AUTHORS.md for complete list of ndncert authors and contributors.
  */
 
+#include "detail/ndncert-common.hpp"
+
 #include "boost-test.hpp"
+
 #include <boost/filesystem.hpp>
 #include <fstream>
 #include <stdlib.h>
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -36,19 +38,22 @@
     if (envHome)
       m_home = envHome;
 
-    boost::filesystem::path dir{TMP_TESTS_PATH};
-    dir /= "test-home";
-    ::setenv("HOME", dir.c_str(), 1);
+    auto testHome = boost::filesystem::path(TMP_TESTS_PATH) / "test-home";
+    if (::setenv("HOME", testHome.c_str(), 1) != 0)
+      NDN_THROW(std::runtime_error("setenv() failed"));
 
-    boost::filesystem::create_directories(dir);
-    std::ofstream clientConf((dir / ".ndn" / "client.conf").c_str());
+    boost::filesystem::create_directories(testHome);
+
+    std::ofstream clientConf((testHome / ".ndn" / "client.conf").c_str());
     clientConf << "pib=pib-sqlite3" << std::endl
                << "tpm=tpm-file" << std::endl;
   }
 
-  ~GlobalConfiguration()
+  ~GlobalConfiguration() noexcept
   {
-    if (!m_home.empty())
+    if (m_home.empty())
+      ::unsetenv("HOME");
+    else
       ::setenv("HOME", m_home.data(), 1);
   }
 
@@ -66,4 +71,3 @@
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
\ No newline at end of file
diff --git a/tests/identity-management-fixture.cpp b/tests/identity-management-fixture.cpp
index 8ca0545..c4a4590 100644
--- a/tests/identity-management-fixture.cpp
+++ b/tests/identity-management-fixture.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -20,15 +20,16 @@
  */
 
 #include "identity-management-fixture.hpp"
+
 #include <ndn-cxx/security/additional-description.hpp>
 #include <ndn-cxx/util/io.hpp>
+
 #include <boost/filesystem.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
-namespace v2 = security::v2;
+using namespace ndn::security;
 
 IdentityManagementBaseFixture::~IdentityManagementBaseFixture()
 {
@@ -43,10 +44,10 @@
 {
   m_certFiles.insert(filename);
   try {
-    io::save(obj, filename);
+    ndn::io::save(obj, filename);
     return true;
   }
-  catch (const io::Error&) {
+  catch (const ndn::io::Error&) {
     return false;
   }
 }
@@ -56,8 +57,8 @@
 {
 }
 
-security::Identity
-IdentityManagementFixture::addIdentity(const Name& identityName, const KeyParams& params)
+Identity
+IdentityManagementFixture::addIdentity(const Name& identityName, const ndn::KeyParams& params)
 {
   auto identity = m_keyChain.createIdentity(identityName, params);
   m_identities.insert(identityName);
@@ -65,32 +66,31 @@
 }
 
 bool
-IdentityManagementFixture::saveCertificate(const security::Identity& identity, const std::string& filename)
+IdentityManagementFixture::saveCertificate(const Identity& identity, const std::string& filename)
 {
   try {
     auto cert = identity.getDefaultKey().getDefaultCertificate();
     return saveCertToFile(cert, filename);
   }
-  catch (const security::Pib::Error&) {
+  catch (const Pib::Error&) {
     return false;
   }
 }
 
-security::Identity
+Identity
 IdentityManagementFixture::addSubCertificate(const Name& subIdentityName,
-                                             const security::Identity& issuer, const KeyParams& params)
+                                             const Identity& issuer, const ndn::KeyParams& params)
 {
   auto subIdentity = addIdentity(subIdentityName, params);
 
-  v2::Certificate request = subIdentity.getDefaultKey().getDefaultCertificate();
-
+  Certificate request = subIdentity.getDefaultKey().getDefaultCertificate();
   request.setName(request.getKeyName().append("parent").appendVersion());
 
   SignatureInfo info;
   auto now = time::system_clock::now();
-  info.setValidityPeriod(security::ValidityPeriod(now, now + 7300_days));
+  info.setValidityPeriod(ValidityPeriod(now, now + 7300_days));
 
-  v2::AdditionalDescription description;
+  AdditionalDescription description;
   description.set("type", "sub-certificate");
   info.addCustomTlv(description.wireEncode());
 
@@ -100,14 +100,14 @@
   return subIdentity;
 }
 
-v2::Certificate
-IdentityManagementFixture::addCertificate(const security::Key& key, const std::string& issuer)
+Certificate
+IdentityManagementFixture::addCertificate(const Key& key, const std::string& issuer)
 {
   Name certificateName = key.getName();
   certificateName
     .append(issuer)
     .appendVersion();
-  v2::Certificate certificate;
+  Certificate certificate;
   certificate.setName(certificateName);
 
   // set metainfo
@@ -120,7 +120,7 @@
   // set signature-info
   SignatureInfo info;
   auto now = time::system_clock::now();
-  info.setValidityPeriod(security::ValidityPeriod(now, now + 10_days));
+  info.setValidityPeriod(ValidityPeriod(now, now + 10_days));
 
   m_keyChain.sign(certificate, signingByKey(key).setSignatureInfo(info));
   return certificate;
@@ -128,4 +128,3 @@
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/identity-management-fixture.hpp b/tests/identity-management-fixture.hpp
index 9b10dbf..7856bf9 100644
--- a/tests/identity-management-fixture.hpp
+++ b/tests/identity-management-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -22,11 +22,11 @@
 #ifndef NDN_TESTS_IDENTITY_MANAGEMENT_FIXTURE_HPP
 #define NDN_TESTS_IDENTITY_MANAGEMENT_FIXTURE_HPP
 
+#include "detail/ndncert-common.hpp"
+
 #include <ndn-cxx/security/key-chain.hpp>
 #include <ndn-cxx/security/signing-helpers.hpp>
-#include <vector>
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -51,6 +51,10 @@
  */
 class IdentityManagementFixture : public IdentityManagementBaseFixture
 {
+protected:
+  using Identity = ndn::security::Identity;
+  using Key      = ndn::security::Key;
+
 public:
   IdentityManagementFixture();
 
@@ -58,9 +62,9 @@
    * @brief Add identity @p identityName
    * @return name of the created self-signed certificate
    */
-  security::Identity
+  Identity
   addIdentity(const Name& identityName,
-              const KeyParams& params = security::KeyChain::getDefaultKeyParams());
+              const ndn::KeyParams& params = ndn::KeyChain::getDefaultKeyParams());
 
   /**
    *  @brief Save identity certificate to a file
@@ -69,7 +73,7 @@
    *  @return whether successful
    */
   bool
-  saveCertificate(const security::Identity& identity, const std::string& filename);
+  saveCertificate(const Identity& identity, const std::string& filename);
 
   /**
    * @brief Issue a certificate for \p subIdentityName signed by \p issuer
@@ -80,22 +84,21 @@
    *
    *  @return the sub identity
    */
-  security::Identity
-  addSubCertificate(const Name& subIdentityName, const security::Identity& issuer,
-                    const KeyParams& params = security::KeyChain::getDefaultKeyParams());
+  Identity
+  addSubCertificate(const Name& subIdentityName, const Identity& issuer,
+                    const ndn::KeyParams& params = ndn::KeyChain::getDefaultKeyParams());
 
   /**
    * @brief Add a self-signed certificate to @p key with issuer ID @p issuer
    */
-  security::Certificate
-  addCertificate(const security::Key& key, const std::string& issuer);
+  Certificate
+  addCertificate(const Key& key, const std::string& issuer);
 
 protected:
-  KeyChain m_keyChain;
+  ndn::KeyChain m_keyChain;
 };
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDN_TESTS_IDENTITY_MANAGEMENT_FIXTURE_HPP
diff --git a/tests/unit-test-time-fixture.hpp b/tests/unit-test-time-fixture.hpp
index cebce38..c497940 100644
--- a/tests/unit-test-time-fixture.hpp
+++ b/tests/unit-test-time-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -22,10 +22,12 @@
 #ifndef NDN_TESTS_UNIT_UNIT_TEST_TIME_FIXTURE_HPP
 #define NDN_TESTS_UNIT_UNIT_TEST_TIME_FIXTURE_HPP
 
+#include "detail/ndncert-common.hpp"
+
 #include <ndn-cxx/util/time-unit-test-clock.hpp>
+
 #include <boost/asio/io_service.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -35,8 +37,8 @@
 {
 public:
   UnitTestTimeFixture()
-    : steadyClock(make_shared<time::UnitTestSteadyClock>())
-    , systemClock(make_shared<time::UnitTestSystemClock>())
+    : steadyClock(std::make_shared<time::UnitTestSteadyClock>())
+    , systemClock(std::make_shared<time::UnitTestSystemClock>())
   {
     time::setCustomClocks(steadyClock, systemClock);
   }
@@ -95,13 +97,12 @@
   }
 
 public:
-  shared_ptr<time::UnitTestSteadyClock> steadyClock;
-  shared_ptr<time::UnitTestSystemClock> systemClock;
+  std::shared_ptr<time::UnitTestSteadyClock> steadyClock;
+  std::shared_ptr<time::UnitTestSystemClock> systemClock;
   boost::asio::io_service io;
 };
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDN_TESTS_UNIT_UNIT_TEST_TIME_FIXTURE_HPP
diff --git a/tests/unit-tests/bench.t.cpp b/tests/unit-tests/bench.t.cpp
index 7e321e3..5dbdb3b 100644
--- a/tests/unit-tests/bench.t.cpp
+++ b/tests/unit-tests/bench.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -24,31 +24,28 @@
 #include "requester-request.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
-BOOST_FIXTURE_TEST_SUITE(TestForBenchmark, IdentityManagementTimeFixture)
+BOOST_FIXTURE_TEST_SUITE(Benchmark, IdentityManagementTimeFixture)
 
 BOOST_AUTO_TEST_CASE(PacketSize0)
 {
-  name::setConventionEncoding(name::Convention::TYPED);
-
   auto identity = addIdentity(Name("/ndn"));
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  ndn::util::DummyClientFace face(io, m_keyChain, {true, true});
   ca::CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
   auto profileData = ca.getCaProfileData();
 
-  Interest interest = MetadataObject::makeDiscoveryInterest(Name("/ndn/CA/INFO"));
+  Interest interest = ndn::MetadataObject::makeDiscoveryInterest(Name("/ndn/CA/INFO"));
   // std::cout << "CA Config discovery Interest Size: " << interest.wireEncode().size() << std::endl;
-  shared_ptr<Interest> infoInterest = nullptr;
+  std::shared_ptr<Interest> infoInterest;
 
   face.setInterestFilter(
-      InterestFilter("/ndn/CA/INFO"),
+      ndn::InterestFilter("/ndn/CA/INFO"),
       [&](const auto&, const Interest& interest) {
         // std::cout << interest.getName() << std::endl;
         if (interest.getName() == profileData.getName()) {
@@ -72,7 +69,7 @@
     else {
       count++;
       // std::cout << "CA Config Data Size: " << response.wireEncode().size() << std::endl;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(ndn::security::verifySignature(response, cert));
       auto contentBlock = response.getContent();
       contentBlock.parse();
       auto caItem = infotlv::decodeDataContent(contentBlock);
@@ -97,25 +94,25 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  ndn::util::DummyClientFace face(io, m_keyChain, {true, true});
   ca::CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   // generate NEW Interest
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
   auto newInterest = state.genNewInterest(Name("/ndn/alice"),
-                                                        time::system_clock::now(),
-                                                          time::system_clock::now() + time::days(1));
+                                          time::system_clock::now(),
+                                          time::system_clock::now() + time::days(1));
 
   // std::cout << "New Interest Size: " << newInterest->wireEncode().size() << std::endl;
 
   // generate CHALLENGE Interest
-  shared_ptr<Interest> challengeInterest = nullptr;
-  shared_ptr<Interest> challengeInterest2 = nullptr;
-  shared_ptr<Interest> challengeInterest3 = nullptr;
+  std::shared_ptr<Interest> challengeInterest;
+  std::shared_ptr<Interest> challengeInterest2;
+  std::shared_ptr<Interest> challengeInterest3;
 
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
@@ -127,7 +124,7 @@
     }
     else if (Name("/ndn/CA/CHALLENGE").isPrefixOf(response.getName()) && count == 0) {
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(ndn::security::verifySignature(response, cert));
 
       state.onChallengeResponse(response);
       BOOST_CHECK(state.m_status == Status::CHALLENGE);
@@ -137,7 +134,7 @@
     }
     else if (Name("/ndn/CA/CHALLENGE").isPrefixOf(response.getName()) && count == 1) {
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(ndn::security::verifySignature(response, cert));
 
       state.onChallengeResponse(response);
       BOOST_CHECK(state.m_status == Status::CHALLENGE);
@@ -153,7 +150,7 @@
     else if (Name("/ndn/CA/CHALLENGE").isPrefixOf(response.getName()) && count == 2) {
       // std::cout << "CHALLENGE Data Size: " << response.wireEncode().size() << std::endl;
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(ndn::security::verifySignature(response, cert));
       state.onChallengeResponse(response);
       BOOST_CHECK(state.m_status == Status::SUCCESS);
     }
@@ -170,8 +167,7 @@
   BOOST_CHECK_EQUAL(count, 3);
 }
 
-BOOST_AUTO_TEST_SUITE_END()  // TestCaConfig
+BOOST_AUTO_TEST_SUITE_END() // Benchmark
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/ca-memory.t.cpp b/tests/unit-tests/ca-memory.t.cpp
index 290e4ca..fd6f9a5 100644
--- a/tests/unit-tests/ca-memory.t.cpp
+++ b/tests/unit-tests/ca-memory.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -22,7 +22,6 @@
 #include "detail/ca-sqlite.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -93,8 +92,7 @@
   BOOST_CHECK_EQUAL(allRequests.size(), 1);
 }
 
-BOOST_AUTO_TEST_SUITE_END()  // TestCaModule
+BOOST_AUTO_TEST_SUITE_END() // TestCaMemory
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/ca-module.t.cpp b/tests/unit-tests/ca-module.t.cpp
index 385f7ef..d4a733d 100644
--- a/tests/unit-tests/ca-module.t.cpp
+++ b/tests/unit-tests/ca-module.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -26,17 +26,18 @@
 #include "requester-request.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
 using namespace ca;
+using ndn::util::DummyClientFace;
+using ndn::security::verifySignature;
 
 BOOST_FIXTURE_TEST_SUITE(TestCaModule, DatabaseFixture)
 
 BOOST_AUTO_TEST_CASE(Initialization)
 {
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   BOOST_CHECK_EQUAL(ca.getCaConf().caProfile.caPrefix, "/ndn");
 
@@ -47,22 +48,20 @@
 
 BOOST_AUTO_TEST_CASE(HandleProfileFetching)
 {
-  name::setConventionEncoding(name::Convention::TYPED);
-
   auto identity = addIdentity(Name("/ndn"));
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
   auto profileData = ca.getCaProfileData();
 
-  Interest interest = MetadataObject::makeDiscoveryInterest(Name("/ndn/CA/INFO"));
-  shared_ptr<Interest> infoInterest = nullptr;
+  Interest interest = ndn::MetadataObject::makeDiscoveryInterest(Name("/ndn/CA/INFO"));
+  std::shared_ptr<Interest> infoInterest = nullptr;
 
   face.setInterestFilter(
-      InterestFilter("/ndn/CA/INFO"),
+      ndn::InterestFilter("/ndn/CA/INFO"),
       [&](const auto&, const Interest& interest) {
         if (interest.getName() == profileData.getName()) {
           face.put(profileData);
@@ -77,12 +76,12 @@
       count++;
       auto block = response.getContent();
       block.parse();
-      infoInterest =std::make_shared<Interest>(Name(block.get(ndn::tlv::Name)).appendSegment(0));
+      infoInterest = std::make_shared<Interest>(Name(block.get(ndn::tlv::Name)).appendSegment(0));
       infoInterest->setCanBePrefix(false);
     }
     else {
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(verifySignature(response, cert));
       auto contentBlock = response.getContent();
       contentBlock.parse();
       auto caItem = infotlv::decodeDataContent(contentBlock);
@@ -107,16 +106,16 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   Interest interest("/ndn/CA/PROBE");
   interest.setCanBePrefix(false);
 
-  Block paramTLV = makeEmptyBlock(ndn::tlv::ApplicationParameters);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, "name"));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "zhiyi"));
+  Block paramTLV = ndn::makeEmptyBlock(ndn::tlv::ApplicationParameters);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, "name"));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "zhiyi"));
   paramTLV.encode();
 
   interest.setApplicationParameters(paramTLV);
@@ -124,7 +123,7 @@
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
     count++;
-    BOOST_CHECK(security::verifySignature(response, cert));
+    BOOST_CHECK(verifySignature(response, cert));
     Block contentBlock = response.getContent();
     contentBlock.parse();
     Block probeResponse = contentBlock.get(tlv::ProbeResponse);
@@ -145,16 +144,16 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   Interest interest("/ndn/CA/PROBE");
   interest.setCanBePrefix(false);
 
-  Block paramTLV = makeEmptyBlock(ndn::tlv::ApplicationParameters);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, "name"));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "zhiyi"));
+  Block paramTLV = ndn::makeEmptyBlock(ndn::tlv::ApplicationParameters);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, "name"));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "zhiyi"));
   paramTLV.encode();
 
   interest.setApplicationParameters(paramTLV);
@@ -162,7 +161,7 @@
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
     count++;
-    BOOST_CHECK(security::verifySignature(response, cert));
+    BOOST_CHECK(verifySignature(response, cert));
     auto contentBlock = response.getContent();
     contentBlock.parse();
     auto probeResponseBlock = contentBlock.get(tlv::ProbeResponse);
@@ -183,16 +182,16 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-5", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   Interest interest("/ndn/CA/PROBE");
   interest.setCanBePrefix(false);
 
-  Block paramTLV = makeEmptyBlock(ndn::tlv::ApplicationParameters);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, "name"));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "zhiyi"));
+  Block paramTLV = ndn::makeEmptyBlock(ndn::tlv::ApplicationParameters);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, "name"));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "zhiyi"));
   paramTLV.encode();
 
   interest.setApplicationParameters(paramTLV);
@@ -200,7 +199,7 @@
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
     count++;
-    BOOST_CHECK(security::verifySignature(response, cert));
+    BOOST_CHECK(verifySignature(response, cert));
     Block contentBlock = response.getContent();
     contentBlock.parse();
 
@@ -212,8 +211,8 @@
       }
     }
     BOOST_CHECK_EQUAL(redirectionItems.size(), 2);
-    BOOST_CHECK_EQUAL(security::extractIdentityFromCertName(redirectionItems[0].getPrefix(-1)), "/ndn/site1");
-    BOOST_CHECK_EQUAL(security::extractIdentityFromCertName(redirectionItems[1].getPrefix(-1)), "/ndn/site1");
+    BOOST_CHECK_EQUAL(ndn::security::extractIdentityFromCertName(redirectionItems[0].getPrefix(-1)), "/ndn/site1");
+    BOOST_CHECK_EQUAL(ndn::security::extractIdentityFromCertName(redirectionItems[1].getPrefix(-1)), "/ndn/site1");
   });
   face.receive(interest);
   advanceClocks(time::milliseconds(20), 60);
@@ -226,13 +225,13 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
   auto interest = state.genNewInterest(Name("/ndn/zhiyi"),
                                        time::system_clock::now(),
@@ -241,7 +240,7 @@
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
     count++;
-    BOOST_CHECK(security::verifySignature(response, cert));
+    BOOST_CHECK(verifySignature(response, cert));
     auto contentBlock = response.getContent();
     contentBlock.parse();
 
@@ -277,13 +276,13 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1");
   advanceClocks(time::milliseconds(20), 60);
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
   auto current_tp = time::system_clock::now();
   auto interest1 = state.genNewInterest(Name("/ndn/zhiyi"), current_tp, current_tp - time::hours(1));
@@ -308,22 +307,23 @@
   auto key = identity.getDefaultKey();
 
   //build expired cert
-  security::Certificate cert;
+  Certificate cert;
   cert.setName(Name(key.getName()).append("self-sign").appendVersion());
   cert.setContentType(ndn::tlv::ContentType_Key);
   cert.setContent(key.getPublicKey().data(), key.getPublicKey().size());
   SignatureInfo signatureInfo;
-  signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now() - time::days(1), time::system_clock::now() - time::seconds(1)));
+  signatureInfo.setValidityPeriod(ndn::security::ValidityPeriod(time::system_clock::now() - time::days(1),
+                                                                time::system_clock::now() - time::seconds(1)));
   m_keyChain.sign(cert, signingByKey(key.getName()).setSignatureInfo(signatureInfo));
   m_keyChain.setDefaultCertificate(key, cert);
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
   auto interest = state.genNewInterest(Name("/ndn/zhiyi"),
                                        time::system_clock::now(),
@@ -349,13 +349,13 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
 
   auto interest1 = state.genNewInterest(Name("/ndn/a"), time::system_clock::now(),
@@ -374,8 +374,7 @@
     }
     else {
       // should successfully get responses
-      BOOST_CHECK_EXCEPTION(readNonNegativeInteger(contentTlv.get(tlv::ErrorCode)), std::runtime_error,
-                            [](const auto& e) { return true; });
+      BOOST_CHECK_THROW(readNonNegativeInteger(contentTlv.get(tlv::ErrorCode)), std::runtime_error);
     }
   });
   face.receive(*interest1);
@@ -390,13 +389,13 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1");
   advanceClocks(time::milliseconds(20), 60);
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
 
   auto current_tp = time::system_clock::now();
@@ -420,23 +419,23 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  DummyClientFace face(io, m_keyChain, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   // generate NEW Interest
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
 
   auto newInterest = state.genNewInterest(Name("/ndn/zhiyi"), time::system_clock::now(),
                                                 time::system_clock::now() + time::days(1));
 
   // generate CHALLENGE Interest
-  shared_ptr<Interest> challengeInterest = nullptr;
-  shared_ptr<Interest> challengeInterest2 = nullptr;
-  shared_ptr<Interest> challengeInterest3 = nullptr;
+  std::shared_ptr<Interest> challengeInterest;
+  std::shared_ptr<Interest> challengeInterest2;
+  std::shared_ptr<Interest> challengeInterest3;
 
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
@@ -447,7 +446,7 @@
     }
     else if (Name("/ndn/CA/CHALLENGE").isPrefixOf(response.getName()) && count == 0) {
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(verifySignature(response, cert));
 
       state.onChallengeResponse(response);
       BOOST_CHECK(state.m_status == Status::CHALLENGE);
@@ -457,7 +456,7 @@
     }
     else if (Name("/ndn/CA/CHALLENGE").isPrefixOf(response.getName()) && count == 1) {
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(verifySignature(response, cert));
 
       state.onChallengeResponse(response);
       BOOST_CHECK(state.m_status == Status::CHALLENGE);
@@ -471,7 +470,7 @@
     }
     else if (Name("/ndn/CA/CHALLENGE").isPrefixOf(response.getName()) && count == 2) {
       count++;
-      BOOST_CHECK(security::verifySignature(response, cert));
+      BOOST_CHECK(verifySignature(response, cert));
       state.onChallengeResponse(response);
       BOOST_CHECK(state.m_status == Status::SUCCESS);
     }
@@ -494,21 +493,21 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, {true, true});
+  DummyClientFace face(io, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   //generate a certificate
   auto clientIdentity = m_keyChain.createIdentity("/ndn/qwerty");
   auto clientKey = clientIdentity.getDefaultKey();
-  security::Certificate clientCert;
+  Certificate clientCert;
   clientCert.setName(Name(clientKey.getName()).append("cert-request").appendVersion());
   clientCert.setContentType(ndn::tlv::ContentType_Key);
   clientCert.setFreshnessPeriod(time::hours(24));
   clientCert.setContent(clientKey.getPublicKey().data(), clientKey.getPublicKey().size());
   SignatureInfo signatureInfo;
-  signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now(),
-                                                           time::system_clock::now() + time::hours(10)));
+  signatureInfo.setValidityPeriod(ndn::security::ValidityPeriod(time::system_clock::now(),
+                                                                time::system_clock::now() + time::hours(10)));
   m_keyChain.sign(clientCert, signingByKey(clientKey.getName()).setSignatureInfo(signatureInfo));
   RequestId requestId = {{101}};
   RequestState certRequest;
@@ -521,7 +520,7 @@
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::REVOKE);
 
   auto interest = state.genRevokeInterest(issuedCert);
@@ -529,7 +528,7 @@
   int count = 0;
   face.onSendData.connect([&](const Data& response) {
     count++;
-    BOOST_CHECK(security::verifySignature(response, cert));
+    BOOST_CHECK(verifySignature(response, cert));
     auto contentBlock = response.getContent();
     contentBlock.parse();
 
@@ -565,26 +564,26 @@
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
 
-  util::DummyClientFace face(io, {true, true});
+  DummyClientFace face(io, {true, true});
   CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-1", "ca-storage-memory");
   advanceClocks(time::milliseconds(20), 60);
 
   // generate a certificate
   auto clientIdentity = m_keyChain.createIdentity("/ndn/qwerty");
   auto clientKey = clientIdentity.getDefaultKey();
-  security::Certificate clientCert;
-  clientCert.setName(Name(clientKey.getName()).append("NDNCERT").append(std::to_string(1473283247810732701)));
+  Certificate clientCert;
+  clientCert.setName(Name(clientKey.getName()).append("NDNCERT").append("1473283247810732701"));
   clientCert.setContentType(ndn::tlv::ContentType_Key);
   clientCert.setFreshnessPeriod(time::hours(24));
   clientCert.setContent(clientKey.getPublicKey().data(), clientKey.getPublicKey().size());
   SignatureInfo signatureInfo;
-  signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now(),
-                                                           time::system_clock::now() + time::hours(10)));
+  signatureInfo.setValidityPeriod(ndn::security::ValidityPeriod(time::system_clock::now(),
+                                                                time::system_clock::now() + time::hours(10)));
   m_keyChain.sign(clientCert, signingByKey(clientKey.getName()).setSignatureInfo(signatureInfo));
 
   CaProfile item;
   item.caPrefix = Name("/ndn");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   requester::Request state(m_keyChain, item, RequestType::NEW);
 
   auto interest = state.genRevokeInterest(clientCert);
@@ -602,8 +601,7 @@
   BOOST_CHECK_EQUAL(receiveData, true);
 }
 
-BOOST_AUTO_TEST_SUITE_END()  // TestCaModule
+BOOST_AUTO_TEST_SUITE_END() // TestCaModule
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/ca-sqlite.t.cpp b/tests/unit-tests/ca-sqlite.t.cpp
index 78077db..c592d47 100644
--- a/tests/unit-tests/ca-sqlite.t.cpp
+++ b/tests/unit-tests/ca-sqlite.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -21,7 +21,6 @@
 #include "detail/ca-sqlite.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -130,8 +129,7 @@
   BOOST_CHECK_THROW(storage.addRequest(request1), std::runtime_error);
 }
 
-BOOST_AUTO_TEST_SUITE_END() // TestCaModule
+BOOST_AUTO_TEST_SUITE_END() // TestCaSqlite
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/challenge-email.t.cpp b/tests/unit-tests/challenge-email.t.cpp
index 8ee9be9..92fb45b 100644
--- a/tests/unit-tests/challenge-email.t.cpp
+++ b/tests/unit-tests/challenge-email.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -21,7 +21,6 @@
 #include "challenge/challenge-email.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -52,9 +51,9 @@
   request.requestType = RequestType::NEW;
   request.cert = cert;
 
-  Block paramTLV = makeEmptyBlock(tlv::EncryptedPayload);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_EMAIL));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "zhiyi@cs.ucla.edu"));
+  Block paramTLV = ndn::makeEmptyBlock(tlv::EncryptedPayload);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_EMAIL));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "zhiyi@cs.ucla.edu"));
 
   ChallengeEmail challenge("./tests/unit-tests/test-send-email.sh");
   challenge.handleChallengeRequest(paramTLV, request);
@@ -106,9 +105,9 @@
   request.requestType = RequestType::NEW;
   request.cert = cert;
 
-  Block paramTLV = makeEmptyBlock(tlv::EncryptedPayload);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_EMAIL));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "zhiyi@cs"));
+  Block paramTLV = ndn::makeEmptyBlock(tlv::EncryptedPayload);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_EMAIL));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "zhiyi@cs"));
 
   ChallengeEmail challenge;
   challenge.handleChallengeRequest(paramTLV, request);
@@ -136,9 +135,9 @@
   request.challengeState = ca::ChallengeState(ChallengeEmail::NEED_CODE, time::system_clock::now(),
                                               3, time::seconds(3600), std::move(secret));
 
-  Block paramTLV = makeEmptyBlock(tlv::EncryptedPayload);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_CODE));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "4567"));
+  Block paramTLV = ndn::makeEmptyBlock(tlv::EncryptedPayload);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_CODE));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "4567"));
 
   ChallengeEmail challenge;
   challenge.handleChallengeRequest(paramTLV, request);
@@ -165,9 +164,9 @@
   request.challengeState = ca::ChallengeState(ChallengeEmail::NEED_CODE, time::system_clock::now(),
                                               3, time::seconds(3600), std::move(secret));
 
-  Block paramTLV = makeEmptyBlock(tlv::EncryptedPayload);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_CODE));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "7890"));
+  Block paramTLV = ndn::makeEmptyBlock(tlv::EncryptedPayload);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, ChallengeEmail::PARAMETER_KEY_CODE));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "7890"));
 
   ChallengeEmail challenge;
   challenge.handleChallengeRequest(paramTLV, request);
@@ -177,8 +176,7 @@
   BOOST_CHECK_EQUAL(request.challengeState->secrets.empty(), false);
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestChallengeEmail
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/challenge-pin.t.cpp b/tests/unit-tests/challenge-pin.t.cpp
index 61167d0..b835089 100644
--- a/tests/unit-tests/challenge-pin.t.cpp
+++ b/tests/unit-tests/challenge-pin.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -21,7 +21,6 @@
 #include "challenge/challenge-pin.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -46,7 +45,7 @@
   request.cert = cert;
 
   ChallengePin challenge;
-  challenge.handleChallengeRequest(makeEmptyBlock(tlv::EncryptedPayload), request);
+  challenge.handleChallengeRequest(ndn::makeEmptyBlock(tlv::EncryptedPayload), request);
 
   BOOST_CHECK(request.status == Status::CHALLENGE);
   BOOST_CHECK_EQUAL(request.challengeState->challengeStatus, ChallengePin::NEED_CODE);
@@ -71,9 +70,9 @@
   request.challengeState = ca::ChallengeState(ChallengePin::NEED_CODE, time::system_clock::now(),
                                               3, time::seconds(3600), std::move(secret));
 
-  Block paramTLV = makeEmptyBlock(tlv::EncryptedPayload);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, ChallengePin::PARAMETER_KEY_CODE));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "12345"));
+  Block paramTLV = ndn::makeEmptyBlock(tlv::EncryptedPayload);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, ChallengePin::PARAMETER_KEY_CODE));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "12345"));
 
   ChallengePin challenge;
   challenge.handleChallengeRequest(paramTLV, request);
@@ -100,9 +99,9 @@
   request.challengeState = ca::ChallengeState(ChallengePin::NEED_CODE, time::system_clock::now(),
                                               3, time::seconds(3600), std::move(secret));
 
-  Block paramTLV = makeEmptyBlock(tlv::EncryptedPayload);
-  paramTLV.push_back(makeStringBlock(tlv::ParameterKey, ChallengePin::PARAMETER_KEY_CODE));
-  paramTLV.push_back(makeStringBlock(tlv::ParameterValue, "45678"));
+  Block paramTLV = ndn::makeEmptyBlock(tlv::EncryptedPayload);
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterKey, ChallengePin::PARAMETER_KEY_CODE));
+  paramTLV.push_back(ndn::makeStringBlock(tlv::ParameterValue, "45678"));
 
   ChallengePin challenge;
   challenge.handleChallengeRequest(paramTLV, request);
@@ -112,8 +111,7 @@
   BOOST_CHECK_EQUAL(request.challengeState->secrets.empty(), false);
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestChallengePin
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/challenge-possession.t.cpp b/tests/unit-tests/challenge-possession.t.cpp
index 84d05d5..2c76c3d 100644
--- a/tests/unit-tests/challenge-possession.t.cpp
+++ b/tests/unit-tests/challenge-possession.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,14 +19,13 @@
  */
 
 #include "challenge/challenge-possession.hpp"
-#include "test-common.hpp"
 #include "detail/challenge-encoder.hpp"
+#include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
-BOOST_FIXTURE_TEST_SUITE(TestChallengeCredential, IdentityManagementFixture)
+BOOST_FIXTURE_TEST_SUITE(TestChallengePossession, IdentityManagementFixture)
 
 BOOST_AUTO_TEST_CASE(LoadConfig)
 {
@@ -65,12 +64,12 @@
   auto identityB = addIdentity(Name("/trust/cert"));
   auto keyB = identityB.getDefaultKey();
   auto credentialName = Name(keyB.getName()).append("Credential").appendVersion();
-  security::Certificate credential;
+  Certificate credential;
   credential.setName(credentialName);
   credential.setContent(keyB.getPublicKey().data(), keyB.getPublicKey().size());
   SignatureInfo signatureInfo;
-  signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now(), time::system_clock::now() +
-                                  time::minutes(1)));
+  signatureInfo.setValidityPeriod(ndn::security::ValidityPeriod(time::system_clock::now(),
+                                                                time::system_clock::now() + time::minutes(1)));
   m_keyChain.sign(credential, signingByCertificate(trustAnchor).setSignatureInfo(signatureInfo));
   m_keyChain.addCertificate(keyB, credential);
 
@@ -83,7 +82,7 @@
   BOOST_CHECK_EQUAL(state.challengeState->challengeStatus, "need-proof");
 
   // reply from server
-  auto nonceBuf = fromHex(state.challengeState->secrets.get("nonce", ""));
+  auto nonceBuf = ndn::fromHex(state.challengeState->secrets.get("nonce", ""));
   std::array<uint8_t, 16> nonce{};
   memcpy(nonce.data(), nonceBuf->data(), 16);
   auto params2 = challenge.getRequestedParameterList(state.status, state.challengeState->challengeStatus);
@@ -118,12 +117,12 @@
   auto identityB = addIdentity(Name("/trust/cert"));
   auto keyB = identityB.getDefaultKey();
   auto credentialName = Name(keyB.getName()).append("Credential").appendVersion();
-  security::Certificate credential;
+  Certificate credential;
   credential.setName(credentialName);
   credential.setContent(keyB.getPublicKey().data(), keyB.getPublicKey().size());
   SignatureInfo signatureInfo;
-  signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now(), time::system_clock::now() +
-                                                                                        time::minutes(1)));
+  signatureInfo.setValidityPeriod(ndn::security::ValidityPeriod(time::system_clock::now(),
+                                                                time::system_clock::now() + time::minutes(1)));
   m_keyChain.sign(credential, signingByCertificate(trustAnchor).setSignatureInfo(signatureInfo));
   m_keyChain.addCertificate(keyB, credential);
 
@@ -144,8 +143,7 @@
   BOOST_CHECK_EQUAL(statusToString(state.status), statusToString(Status::FAILURE));
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestChallengePossession
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/configuration.t.cpp b/tests/unit-tests/configuration.t.cpp
index 20748d9..f7a8bc5 100644
--- a/tests/unit-tests/configuration.t.cpp
+++ b/tests/unit-tests/configuration.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,13 +23,12 @@
 #include "detail/info-encoder.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
 BOOST_FIXTURE_TEST_SUITE(TestConfig, IdentityManagementFixture)
 
-BOOST_AUTO_TEST_CASE(CAConfigFile)
+BOOST_AUTO_TEST_CASE(CaConfigFile)
 {
   ca::CaConfig config;
   config.load("tests/unit-tests/config-files/config-ca-1");
@@ -73,7 +72,7 @@
   BOOST_CHECK_EQUAL(names[2].size(), 1);
 }
 
-BOOST_AUTO_TEST_CASE(CAConfigFileWithErrors)
+BOOST_AUTO_TEST_CASE(CaConfigFileWithErrors)
 {
   ca::CaConfig config;
   // nonexistent file
@@ -143,8 +142,7 @@
   BOOST_CHECK_EQUAL(lastItem.caPrefix, "/ndn/edu/ucla/zhiyi");
 }
 
-BOOST_AUTO_TEST_SUITE_END()  // TestCaConfig
+BOOST_AUTO_TEST_SUITE_END() // TestConfig
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/crypto-helpers.t.cpp b/tests/unit-tests/crypto-helpers.t.cpp
index 9025da0..008a2f6 100644
--- a/tests/unit-tests/crypto-helpers.t.cpp
+++ b/tests/unit-tests/crypto-helpers.t.cpp
@@ -21,7 +21,6 @@
 #include "detail/crypto-helpers.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -281,7 +280,7 @@
                                         (uint8_t*)associatedData.c_str(), associatedData.size(), encryptionIv);
   block.parse();
   auto ivBlock = block.get(tlv::InitializationVector);
-  Buffer ivBuf(ivBlock.value(), ivBlock.value_size());
+  ndn::Buffer ivBuf(ivBlock.value(), ivBlock.value_size());
   BOOST_CHECK_EQUAL(ivBuf.size(), 12);
   BOOST_CHECK_EQUAL(loadBigU32(&encryptionIv[8]), 6);
   BOOST_CHECK_EQUAL(loadBigU32(&ivBuf[8]), 0);
@@ -290,7 +289,7 @@
                                    (uint8_t*)associatedData.c_str(), associatedData.size(), encryptionIv);
   block.parse();
   ivBlock = block.get(tlv::InitializationVector);
-  Buffer ivBuf2(ivBlock.value(), ivBlock.value_size());
+  ndn::Buffer ivBuf2(ivBlock.value(), ivBlock.value_size());
   BOOST_CHECK_EQUAL(std::memcmp(ivBuf2.data(), encryptionIv.data(), 8), 0);
 }
 
@@ -338,8 +337,7 @@
                     std::runtime_error);
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestCryptoHelpers
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/name-assignment.t.cpp b/tests/unit-tests/name-assignment.t.cpp
index 425e513..94b7fef 100644
--- a/tests/unit-tests/name-assignment.t.cpp
+++ b/tests/unit-tests/name-assignment.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,11 +23,11 @@
 #include "name-assignment/assignment-hash.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
 BOOST_AUTO_TEST_SUITE(TestNameAssignment)
+
 BOOST_AUTO_TEST_CASE(NameAssignmentRandom)
 {
   AssignmentRandom assignment;
@@ -68,10 +68,7 @@
   BOOST_CHECK_EQUAL(assignment.assignName(params).begin()->size(), 2);
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestNameAssignment
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
-
-
diff --git a/tests/unit-tests/protocol-encoders.t.cpp b/tests/unit-tests/protocol-encoders.t.cpp
index 61128e3..bc1daa0 100644
--- a/tests/unit-tests/protocol-encoders.t.cpp
+++ b/tests/unit-tests/protocol-encoders.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -25,9 +25,7 @@
 #include "detail/probe-encoder.hpp"
 #include "detail/ca-configuration.hpp"
 #include "test-common.hpp"
-#include "identity-management-fixture.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -108,7 +106,7 @@
   std::vector<uint8_t> pub = ECDHState().getSelfPubKey();
   auto b = requesttlv::encodeApplicationParameters(RequestType::REVOKE, pub, *certRequest);
   std::vector<uint8_t> returnedPub;
-  std::shared_ptr<security::Certificate> returnedCert;
+  std::shared_ptr<Certificate> returnedCert;
   requesttlv::decodeApplicationParameters(b, RequestType::REVOKE, returnedPub, returnedCert);
 
   BOOST_CHECK_EQUAL(returnedPub.size(), pub.size());
@@ -143,7 +141,7 @@
                          0xe0, 0xff, 0x56, 0x83, 0xf2, 0x43, 0xb2, 0x13};
   requester::ProfileStorage caCache;
   caCache.load("tests/unit-tests/config-files/config-client-1");
-  security::Certificate certRequest = *caCache.getKnownProfiles().front().cert;
+  auto certRequest = *caCache.getKnownProfiles().front().cert;
   RequestId id = {{102}};
   ca::RequestState state;
   state.caPrefix = Name("/ndn/ucla");
@@ -170,8 +168,7 @@
   BOOST_CHECK_EQUAL(context.m_issuedCertName, "/ndn/ucla/a/b/c");
 }
 
-BOOST_AUTO_TEST_SUITE_END()
+BOOST_AUTO_TEST_SUITE_END() // TestProtocolEncoding
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tests/unit-tests/requester.t.cpp b/tests/unit-tests/requester.t.cpp
index 1f07a3f..d2833c4 100644
--- a/tests/unit-tests/requester.t.cpp
+++ b/tests/unit-tests/requester.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -25,7 +25,6 @@
 #include "ca-module.hpp"
 #include "test-common.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace tests {
 
@@ -33,7 +32,6 @@
 
 BOOST_FIXTURE_TEST_SUITE(TestRequester, IdentityManagementTimeFixture)
 
-/* PROBE */
 BOOST_AUTO_TEST_CASE(GenProbeInterest)
 {
   auto identity = addIdentity(Name("/site"));
@@ -45,7 +43,7 @@
   ca_profile.probeParameterKeys.push_back("uid");
   ca_profile.probeParameterKeys.push_back("name");
   ca_profile.caPrefix = Name("/site");
-  ca_profile.cert = std::make_shared<security::Certificate>(cert);
+  ca_profile.cert = std::make_shared<Certificate>(cert);
 
   std::multimap<std::string, std::string> probeParams;
   probeParams.emplace("email", "zhiyi@cs.ucla.edu");
@@ -69,20 +67,20 @@
   ca_profile.probeParameterKeys.push_back("uid");
   ca_profile.probeParameterKeys.push_back("name");
   ca_profile.caPrefix = Name("/site");
-  ca_profile.cert = std::make_shared<security::Certificate>(cert);
+  ca_profile.cert = std::make_shared<Certificate>(cert);
 
   std::vector<Name> availableNames;
   availableNames.push_back(Name("/site1"));
   availableNames.push_back(Name("/site2"));
 
-  util::DummyClientFace face(io, m_keyChain, {true, true});
+  ndn::util::DummyClientFace face(io, m_keyChain, {true, true});
   ca::CaModule ca(face, m_keyChain, "tests/unit-tests/config-files/config-ca-5", "ca-storage-memory");
 
   Data reply;
   reply.setName(Name("/site/CA/PROBE"));
   reply.setFreshnessPeriod(time::seconds(100));
   reply.setContent(probetlv::encodeDataContent(availableNames, 3, ca.m_config.redirection));
-  m_keyChain.sign(reply, signingByIdentity(identity));
+  m_keyChain.sign(reply, ndn::signingByIdentity(identity));
 
   std::vector<std::pair<Name, int>> names;
   std::vector<Name> redirects;
@@ -96,8 +94,8 @@
   BOOST_CHECK_EQUAL(names[1].second, 3);
 
   BOOST_CHECK_EQUAL(redirects.size(), 2);
-  BOOST_CHECK_EQUAL(security::extractIdentityFromCertName(redirects[0].getPrefix(-1)), "/ndn/site1");
-  BOOST_CHECK_EQUAL(security::extractIdentityFromCertName(redirects[1].getPrefix(-1)), "/ndn/site1");
+  BOOST_CHECK_EQUAL(ndn::security::extractIdentityFromCertName(redirects[0].getPrefix(-1)), "/ndn/site1");
+  BOOST_CHECK_EQUAL(ndn::security::extractIdentityFromCertName(redirects[1].getPrefix(-1)), "/ndn/site1");
 }
 
 BOOST_AUTO_TEST_CASE(ErrorHandling)
@@ -108,14 +106,14 @@
 
   CaProfile item;
   item.caPrefix = Name("/site");
-  item.cert = std::make_shared<security::Certificate>(cert);
+  item.cert = std::make_shared<Certificate>(cert);
   Request state(m_keyChain, item, RequestType::NEW);
 
   Data errorPacket;
   errorPacket.setName(Name("/site/pretend/this/is/error/packet"));
   errorPacket.setFreshnessPeriod(time::seconds(100));
   errorPacket.setContent(errortlv::encodeDataContent(ErrorCode::INVALID_PARAMETER, "This is a test."));
-  m_keyChain.sign(errorPacket, signingByIdentity(identity));
+  m_keyChain.sign(errorPacket, ndn::signingByIdentity(identity));
 
   std::vector<std::pair<Name, int>> ids;
   std::vector<Name> cas;
@@ -128,4 +126,3 @@
 
 } // namespace tests
 } // namespace ndncert
-} // namespace ndn
diff --git a/tools/ndncert-ca-server.cpp b/tools/ndncert-ca-server.cpp
index 697960f..5f0e3a3 100644
--- a/tools/ndncert-ca-server.cpp
+++ b/tools/ndncert-ca-server.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2017-2020, Regents of the University of California.
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,6 +19,7 @@
  */
 
 #include "ca-module.hpp"
+
 #include <boost/asio.hpp>
 #include <boost/asio/ip/tcp.hpp>
 #include <boost/program_options/options_description.hpp>
@@ -27,17 +28,17 @@
 #include <iostream>
 #include <chrono>
 #include <deque>
+
 #include <ndn-cxx/face.hpp>
 #include <ndn-cxx/security/key-chain.hpp>
 
-namespace ndn {
 namespace ndncert {
 namespace ca {
 
-Face face;
-security::KeyChain keyChain;
-std::string repoHost = "localhost";
-std::string repoPort = "7376";
+static ndn::Face face;
+static ndn::KeyChain keyChain;
+static std::string repoHost = "localhost";
+static std::string repoPort = "7376";
 const size_t MAX_CACHED_CERT_NUM = 100;
 
 static bool
@@ -141,8 +142,8 @@
       }
     });
     face.setInterestFilter(
-        InterestFilter(ca.getCaConf().caProfile.caPrefix),
-        [&](const InterestFilter&, const Interest& interest) {
+        ndn::InterestFilter(ca.getCaConf().caProfile.caPrefix),
+        [&](const auto&, const auto& interest) {
           const auto& interestName = interest.getName();
           if (interestName.isPrefixOf(profileData.getName())) {
             face.put(profileData);
@@ -166,10 +167,9 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 int
 main(int argc, char* argv[])
 {
-  return ndn::ndncert::ca::main(argc, argv);
+  return ndncert::ca::main(argc, argv);
 }
diff --git a/tools/ndncert-ca-status.cpp b/tools/ndncert-ca-status.cpp
index 0db2353..2d0c0f9 100644
--- a/tools/ndncert-ca-status.cpp
+++ b/tools/ndncert-ca-status.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,16 +20,17 @@
 
 #include "ca-module.hpp"
 #include "detail/ca-sqlite.hpp"
-#include <iostream>
+
 #include <boost/program_options/options_description.hpp>
 #include <boost/program_options/variables_map.hpp>
 #include <boost/program_options/parsers.hpp>
 
-namespace ndn {
+#include <iostream>
+
 namespace ndncert {
 namespace ca {
 
-int
+static int
 main(int argc, char* argv[])
 {
   namespace po = boost::program_options;
@@ -75,10 +76,9 @@
 
 } // namespace ca
 } // namespace ndncert
-} // namespace ndn
 
 int
 main(int argc, char* argv[])
 {
-  return ndn::ndncert::ca::main(argc, argv);
+  return ndncert::ca::main(argc, argv);
 }
diff --git a/tools/ndncert-client.cpp b/tools/ndncert-client.cpp
index fec4aa1..30c7454 100644
--- a/tools/ndncert-client.cpp
+++ b/tools/ndncert-client.cpp
@@ -20,6 +20,8 @@
 
 #include "requester-request.hpp"
 
+#include <ndn-cxx/face.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
 #include <ndn-cxx/security/verification-helpers.hpp>
 
 #include <boost/asio.hpp>
@@ -29,7 +31,6 @@
 
 #include <iostream>
 
-namespace ndn {
 namespace ndncert {
 namespace requester {
 
@@ -46,9 +47,9 @@
 runChallenge(const std::string& challengeType);
 
 static size_t nStep = 1;
-static Face face;
-static security::KeyChain keyChain;
-static shared_ptr<Request> requesterState;
+static ndn::Face face;
+static ndn::KeyChain keyChain;
+static std::shared_ptr<Request> requesterState;
 
 static void
 captureParams(std::multimap<std::string, std::string>& requirement)
@@ -92,7 +93,7 @@
     try {
       return std::stoul(periodStr);
     }
-    catch (const std::exception& e) {
+    catch (const std::exception&) {
       std::cerr << "Your input is invalid. Try again: " << std::endl;
       count++;
     }
@@ -183,7 +184,7 @@
       try {
         challengeIndex = std::stoul(choice);
       }
-      catch (const std::exception& e) {
+      catch (const std::exception&) {
         std::cerr << "Your input is not valid. Try again:" << std::endl;
         inputCount++;
         continue;
@@ -262,7 +263,8 @@
   std::cerr << "\nOr choose another trusted CA suggested by the CA: " << std::endl;
   for (const auto& redirect : redirects) {
     std::cerr << "> Index: " << count++ << std::endl
-              << ">> Suggested CA: " << security::extractIdentityFromCertName(redirect.getPrefix(-1)) << std::endl;
+              << ">> Suggested CA: " << ndn::security::extractIdentityFromCertName(redirect.getPrefix(-1))
+              << std::endl;
   }
   std::cerr << "Please type in the index of your choice:" << std::endl;
   size_t index = 0;
@@ -271,7 +273,7 @@
     getline(std::cin, input);
     index = std::stoul(input);
   }
-  catch (const std::exception& e) {
+  catch (const std::exception&) {
     std::cerr << "Your input is Invalid. Exit" << std::endl;
     exit(1);
   }
@@ -293,7 +295,7 @@
         std::cerr << "You are applying name: " << selectedName.toUri() << std::endl;
       }
     }
-    catch (const std::exception& e) {
+    catch (const std::exception&) {
       std::cerr << "Your input is Invalid. Exit" << std::endl;
       exit(1);
     }
@@ -302,7 +304,7 @@
   else {
     //redirects
     auto redirectedCaFullName = redirects[index - names.size()];
-    auto redirectedCaName = security::extractIdentityFromCertName(redirectedCaFullName.getPrefix(-1));
+    auto redirectedCaName = ndn::security::extractIdentityFromCertName(redirectedCaFullName.getPrefix(-1));
     std::cerr << "You selected to be redirected to CA: " << redirectedCaName.toUri() << std::endl;
     face.expressInterest(
         *Request::genCaProfileDiscoveryInterest(redirectedCaName),
@@ -365,7 +367,7 @@
     try {
       caIndex = std::stoul(caIndexS);
     }
-    catch (const std::exception& e) {
+    catch (const std::exception&) {
       std::cerr << "Your input is neither NONE nor a valid index. Exit" << std::endl;
       return;
     }
@@ -532,10 +534,9 @@
 
 } // namespace requester
 } // namespace ndncert
-} // namespace ndn
 
 int
 main(int argc, char* argv[])
 {
-  return ndn::ndncert::requester::main(argc, argv);
+  return ndncert::requester::main(argc, argv);
 }