diff --git a/src/ca-detail/ca-memory.cpp b/src/ca-detail/ca-memory.cpp
index ce5bd98..d6f6563 100644
--- a/src/ca-detail/ca-memory.cpp
+++ b/src/ca-detail/ca-memory.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2019, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -20,6 +20,8 @@
 
 #include "ca-memory.hpp"
 
+#include <ndn-cxx/security/validation-policy.hpp>
+
 namespace ndn {
 namespace ndncert {
 
@@ -103,22 +105,18 @@
 }
 
 // certificate related
-security::v2::Certificate
+security::Certificate
 CaMemory::getCertificate(const std::string& certId)
 {
-  security::v2::Certificate cert;
   auto search = m_issuedCerts.find(certId);
   if (search != m_issuedCerts.end()) {
-    cert = search->second;
-    return cert;
+    return search->second;
   }
-  else {
-    BOOST_THROW_EXCEPTION(Error("Certificate with ID " + certId + " does not exists"));
-  }
+  BOOST_THROW_EXCEPTION(Error("Certificate with ID " + certId + " does not exists"));
 }
 
 void
-CaMemory::addCertificate(const std::string& certId, const security::v2::Certificate& cert)
+CaMemory::addCertificate(const std::string& certId, const security::Certificate& cert)
 {
   auto search = m_issuedCerts.find(certId);
   if (search == m_issuedCerts.end()) {
@@ -130,7 +128,7 @@
 }
 
 void
-CaMemory::updateCertificate(const std::string& certId, const security::v2::Certificate& cert)
+CaMemory::updateCertificate(const std::string& certId, const security::Certificate& cert)
 {
   m_issuedCerts[certId] = cert;
 }
@@ -144,22 +142,23 @@
   }
 }
 
-std::list<security::v2::Certificate>
+std::list<security::Certificate>
 CaMemory::listAllIssuedCertificates()
 {
-  std::list<security::v2::Certificate> result;
+  std::list<security::Certificate> result;
   for (const auto& entry : m_issuedCerts) {
     result.push_back(entry.second);
   }
   return result;
 }
 
-std::list<security::v2::Certificate>
+std::list<security::Certificate>
 CaMemory::listAllIssuedCertificates(const Name& caName)
 {
-  std::list<security::v2::Certificate> result;
+  std::list<security::Certificate> result;
   for (const auto& entry : m_issuedCerts) {
-    if (entry.second.getSignature().getKeyLocator().getName().getPrefix(-2) == caName) {
+    const auto& klName = entry.second.getSignatureInfo().getKeyLocator().getName();
+    if (security::extractIdentityNameFromKeyLocator(klName) == caName) {
       result.push_back(entry.second);
     }
   }
diff --git a/src/ca-detail/ca-memory.hpp b/src/ca-detail/ca-memory.hpp
index d695359..fb61218 100644
--- a/src/ca-detail/ca-memory.hpp
+++ b/src/ca-detail/ca-memory.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -52,27 +52,27 @@
   listAllRequests(const Name& caName) override;
 
   // certificate related
-  security::v2::Certificate
+  security::Certificate
   getCertificate(const std::string& certId) override;
 
   void
-  addCertificate(const std::string& certId, const security::v2::Certificate& cert) override;
+  addCertificate(const std::string& certId, const security::Certificate& cert) override;
 
   void
-  updateCertificate(const std::string& certId, const security::v2::Certificate& cert) override;
+  updateCertificate(const std::string& certId, const security::Certificate& cert) override;
 
   void
   deleteCertificate(const std::string& certId) override;
 
-  std::list<security::v2::Certificate>
+  std::list<security::Certificate>
   listAllIssuedCertificates() override;
 
-  std::list<security::v2::Certificate>
+  std::list<security::Certificate>
   listAllIssuedCertificates(const Name& caName) override;
 
 private:
   std::map<std::string, CertificateRequest> m_requests;
-  std::map<std::string, security::v2::Certificate> m_issuedCerts;
+  std::map<std::string, security::Certificate> m_issuedCerts;
 };
 
 } // namespace ndncert
diff --git a/src/ca-detail/ca-sqlite.cpp b/src/ca-detail/ca-sqlite.cpp
index cf53022..6b5b4a2 100644
--- a/src/ca-detail/ca-sqlite.cpp
+++ b/src/ca-detail/ca-sqlite.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2019, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -19,6 +19,8 @@
  */
 
 #include "ca-sqlite.hpp"
+
+#include <ndn-cxx/security/validation-policy.hpp>
 #include <ndn-cxx/util/sqlite3-statement.hpp>
 
 #include <sqlite3.h>
@@ -27,8 +29,7 @@
 namespace ndn {
 namespace ndncert {
 
-const std::string
-CaSqlite::STORAGE_TYPE = "ca-storage-sqlite3";
+const std::string CaSqlite::STORAGE_TYPE = "ca-storage-sqlite3";
 
 NDNCERT_REGISTER_CA_STORAGE(CaSqlite);
 
@@ -99,7 +100,7 @@
 
   // initialize database specific tables
   char* errorMessage = nullptr;
-  result = sqlite3_exec(m_database, INITIALIZATION.c_str(),
+  result = sqlite3_exec(m_database, INITIALIZATION.data(),
                         nullptr, nullptr, &errorMessage);
   if (result != SQLITE_OK && errorMessage != nullptr) {
     sqlite3_free(errorMessage);
@@ -124,7 +125,7 @@
     Name caName(statement.getBlock(2));
     int status = statement.getInt(3);
     std::string challengeStatus = statement.getString(4);
-    security::v2::Certificate cert(statement.getBlock(6));
+    security::Certificate cert(statement.getBlock(6));
     std::string challengeType = statement.getString(7);
     std::string challengeSecrets = statement.getString(8);
     std::string challengeTp = statement.getString(9);
@@ -244,12 +245,12 @@
   std::list<CertificateRequest> result;
   Sqlite3Statement statement(m_database, R"_SQLTEXT_(SELECT * FROM CertRequests)_SQLTEXT_");
 
-  while(statement.step() == SQLITE_ROW) {
+  while (statement.step() == SQLITE_ROW) {
     std::string requestId = statement.getString(1);
     Name caName(statement.getBlock(2));
     int status = statement.getInt(3);
     std::string challengeStatus = statement.getString(4);
-    security::v2::Certificate cert(statement.getBlock(6));
+    security::Certificate cert(statement.getBlock(6));
     std::string challengeType = statement.getString(7);
     std::string challengeSecrets = statement.getString(8);
     std::string challengeTp = statement.getString(9);
@@ -271,12 +272,12 @@
                              R"_SQLTEXT_(SELECT * FROM CertRequests WHERE ca_name = ?)_SQLTEXT_");
   statement.bind(1, caName.wireEncode(), SQLITE_TRANSIENT);
 
-  while(statement.step() == SQLITE_ROW) {
+  while (statement.step() == SQLITE_ROW) {
     std::string requestId = statement.getString(1);
     Name caName(statement.getBlock(2));
     int status = statement.getInt(3);
     std::string challengeStatus = statement.getString(4);
-    security::v2::Certificate cert(statement.getBlock(6));
+    security::Certificate cert(statement.getBlock(6));
     std::string challengeType = statement.getString(7);
     std::string challengeSecrets = statement.getString(8);
     std::string challengeTp = statement.getString(9);
@@ -299,7 +300,7 @@
   statement.step();
 }
 
-security::v2::Certificate
+security::Certificate
 CaSqlite::getCertificate(const std::string& certId)
 {
   Sqlite3Statement statement(m_database,
@@ -307,8 +308,7 @@
   statement.bind(1, certId, SQLITE_TRANSIENT);
 
   if (statement.step() == SQLITE_ROW) {
-    security::v2::Certificate cert(statement.getBlock(0));
-    return cert;
+    return security::Certificate(statement.getBlock(0));
   }
   else {
     BOOST_THROW_EXCEPTION(Error("Certificate with ID " + certId + " cannot be fetched from database"));
@@ -316,7 +316,7 @@
 }
 
 void
-CaSqlite::addCertificate(const std::string& certId, const security::v2::Certificate& cert)
+CaSqlite::addCertificate(const std::string& certId, const security::Certificate& cert)
 {
   Sqlite3Statement statement(m_database,
                              R"_SQLTEXT_(INSERT INTO IssuedCerts (cert_id, cert_key_name, cert)
@@ -331,7 +331,7 @@
 }
 
 void
-CaSqlite::updateCertificate(const std::string& certId, const security::v2::Certificate& cert)
+CaSqlite::updateCertificate(const std::string& certId, const security::Certificate& cert)
 {
   Sqlite3Statement statement(m_database,
                              R"_SQLTEXT_(UPDATE IssuedCerts SET cert = ? WHERE cert_id = ?)_SQLTEXT_");
@@ -352,26 +352,26 @@
   statement.step();
 }
 
-std::list<security::v2::Certificate>
+std::list<security::Certificate>
 CaSqlite::listAllIssuedCertificates()
 {
-  std::list<security::v2::Certificate> result;
+  std::list<security::Certificate> result;
   Sqlite3Statement statement(m_database, R"_SQLTEXT_(SELECT * FROM IssuedCerts)_SQLTEXT_");
 
   while (statement.step() == SQLITE_ROW) {
-    security::v2::Certificate cert(statement.getBlock(3));
-    result.push_back(cert);
+    result.emplace_back(statement.getBlock(3));
   }
   return result;
 }
 
-std::list<security::v2::Certificate>
+std::list<security::Certificate>
 CaSqlite::listAllIssuedCertificates(const Name& caName)
 {
   auto allCerts = listAllIssuedCertificates();
-  std::list<security::v2::Certificate> result;
+  std::list<security::Certificate> result;
   for (const auto& entry : allCerts) {
-    if (entry.getSignature().getKeyLocator().getName().getPrefix(-2) == caName) {
+    const auto& klName = entry.getSignatureInfo().getKeyLocator().getName();
+    if (security::extractIdentityNameFromKeyLocator(klName) == caName) {
       result.push_back(entry);
     }
   }
diff --git a/src/ca-detail/ca-sqlite.hpp b/src/ca-detail/ca-sqlite.hpp
index 6249db5..9b09e1a 100644
--- a/src/ca-detail/ca-sqlite.hpp
+++ b/src/ca-detail/ca-sqlite.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -60,22 +60,22 @@
   listAllRequests(const Name& caName) override;
 
   // certificate related
-  security::v2::Certificate
+  security::Certificate
   getCertificate(const std::string& certId) override;
 
   void
-  addCertificate(const std::string& certId, const security::v2::Certificate& cert) override;
+  addCertificate(const std::string& certId, const security::Certificate& cert) override;
 
   void
-  updateCertificate(const std::string& certId, const security::v2::Certificate& cert) override;
+  updateCertificate(const std::string& certId, const security::Certificate& cert) override;
 
   void
   deleteCertificate(const std::string& certId) override;
 
-  std::list<security::v2::Certificate>
+  std::list<security::Certificate>
   listAllIssuedCertificates() override;
 
-  std::list<security::v2::Certificate>
+  std::list<security::Certificate>
   listAllIssuedCertificates(const Name& caName) override;
 
 PUBLIC_WITH_TESTS_ELSE_PRIVATE:
diff --git a/src/ca-module.cpp b/src/ca-module.cpp
index 7dbb053..5e789f7 100644
--- a/src/ca-module.cpp
+++ b/src/ca-module.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2019, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -127,7 +127,7 @@
   }
   else {
     // if not a PROBE INFO, find an available name
-    std::string availableId = "";
+    std::string availableId;
     const auto& parameterJson = jsonFromBlock(request.getApplicationParameters());
     if (parameterJson.empty()) {
       _LOG_ERROR("Empty JSON obtained from the Interest parameter.");
@@ -459,7 +459,7 @@
 CertificateRequest
 CaModule::getCertificateRequest(const Interest& request)
 {
-  std::string requestId = "";
+  std::string requestId;
   CertificateRequest certRequest;
   try {
     requestId = readString(request.getName().at(m_config.m_caName.size() + 2));
@@ -539,9 +539,9 @@
   const auto& pib = m_keyChain.getPib();
   const auto& identity = pib.getIdentity(m_config.m_caName);
   const auto& cert = identity.getDefaultKey().getDefaultCertificate();
-  std::string caInfo = "";
-  if (m_config.m_caInfo == "") {
-    caInfo = "Issued by " + cert.getSignature().getKeyLocator().getName().toUri();
+  std::string caInfo;
+  if (m_config.m_caInfo.empty()) {
+    caInfo = "Issued by " + cert.getSignatureInfo().getKeyLocator().getName().toUri();
   }
   else {
     caInfo = m_config.m_caInfo;
diff --git a/src/challenge-module/challenge-credential.cpp b/src/challenge-module/challenge-credential.cpp
index f5d7434..69a6bbe 100644
--- a/src/challenge-module/challenge-credential.cpp
+++ b/src/challenge-module/challenge-credential.cpp
@@ -1,5 +1,5 @@
-/**
- * Copyright (c) 2017-2019, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2020, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -38,7 +38,7 @@
 ChallengeCredential::ChallengeCredential(const std::string& configPath)
   : ChallengeModule("Credential")
 {
-  if (configPath == "") {
+  if (configPath.empty()) {
     m_configFile = std::string(SYSCONFDIR) + "/ndncert/challenge-credential.conf";
   }
   else {
@@ -109,7 +109,7 @@
   ss2.clear();
 
   // verify the credential and the self-signed cert
-  Name signingKeyName = cert->getSignature().getKeyLocator().getName();
+  Name signingKeyName = cert->getSignatureInfo().getKeyLocator().getName();
   for (auto anchor : m_trustAnchors) {
     if (anchor.getKeyName() == signingKeyName) {
       if (security::verifySignature(*cert, anchor) && security::verifySignature(*self, *cert)