diff --git a/tests/unit/security/key-chain.t.cpp b/tests/unit/security/key-chain.t.cpp
new file mode 100644
index 0000000..6e85b75
--- /dev/null
+++ b/tests/unit/security/key-chain.t.cpp
@@ -0,0 +1,482 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2020 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "ndn-cxx/security/key-chain.hpp"
+#include "ndn-cxx/security/signing-helpers.hpp"
+#include "ndn-cxx/security/verification-helpers.hpp"
+#include "ndn-cxx/security/transform/private-key.hpp"
+
+#include "tests/boost-test.hpp"
+#include "tests/identity-management-fixture.hpp"
+#include "tests/unit/test-home-env-saver.hpp"
+
+namespace ndn {
+namespace security {
+inline namespace v2 {
+namespace tests {
+
+using namespace ndn::tests;
+
+BOOST_AUTO_TEST_SUITE(Security)
+BOOST_FIXTURE_TEST_SUITE(TestKeyChain, TestHomeEnvSaver)
+
+template<class Path>
+class TestHomeAndPibFixture : public TestHomeFixture<Path>
+{
+public:
+  TestHomeAndPibFixture()
+  {
+    unsetenv("NDN_CLIENT_PIB");
+    unsetenv("NDN_CLIENT_TPM");
+  }
+
+  ~TestHomeAndPibFixture()
+  {
+    try {
+      const_cast<std::string&>(KeyChain::getDefaultPibLocator()).clear();
+    }
+    catch (const KeyChain::Error&) {
+      // ignore
+    }
+
+    try {
+      const_cast<std::string&>(KeyChain::getDefaultTpmLocator()).clear();
+    }
+    catch (const KeyChain::Error&) {
+      // ignore
+    }
+  }
+};
+
+struct PibPathConfigFileHome
+{
+  const std::string PATH = "build/config-file-home/";
+};
+
+BOOST_FIXTURE_TEST_CASE(ConstructorNormalConfig, TestHomeAndPibFixture<PibPathConfigFileHome>)
+{
+  createClientConf({"pib=pib-memory:", "tpm=tpm-memory:"});
+
+  BOOST_REQUIRE_NO_THROW(KeyChain());
+
+  KeyChain keyChain;
+  BOOST_CHECK_EQUAL(keyChain.getPib().getPibLocator(), "pib-memory:");
+  BOOST_CHECK_EQUAL(keyChain.getPib().getTpmLocator(), "tpm-memory:");
+  BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-memory:");
+}
+
+struct PibPathConfigFileEmptyHome
+{
+  const std::string PATH = "build/config-file-empty-home/";
+};
+
+BOOST_FIXTURE_TEST_CASE(ConstructorEmptyConfig, TestHomeAndPibFixture<PibPathConfigFileEmptyHome>)
+{
+  createClientConf({"pib=pib-memory:"});
+
+#if defined(NDN_CXX_HAVE_OSX_FRAMEWORKS)
+  std::string oldHOME;
+  if (std::getenv("OLD_HOME"))
+    oldHOME = std::getenv("OLD_HOME");
+
+  std::string HOME;
+  if (std::getenv("HOME"))
+    HOME = std::getenv("HOME");
+
+  if (!oldHOME.empty())
+    setenv("HOME", oldHOME.c_str(), 1);
+  else
+    unsetenv("HOME");
+#endif
+
+  BOOST_REQUIRE_NO_THROW(KeyChain());
+  KeyChain keyChain;
+  BOOST_CHECK_EQUAL(keyChain.getPib().getPibLocator(), "pib-memory:");
+
+#if defined(NDN_CXX_HAVE_OSX_FRAMEWORKS)
+  BOOST_CHECK_EQUAL(keyChain.getPib().getTpmLocator(), "tpm-osxkeychain:");
+  BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-osxkeychain:");
+#else
+  BOOST_CHECK_EQUAL(keyChain.getPib().getTpmLocator(), "tpm-file:");
+  BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-file:");
+#endif
+
+#if defined(NDN_CXX_HAVE_OSX_FRAMEWORKS)
+  if (!HOME.empty())
+    setenv("HOME", HOME.c_str(), 1);
+  else
+    unsetenv("HOME");
+
+  if (!oldHOME.empty())
+    setenv("OLD_HOME", oldHOME.c_str(), 1);
+  else
+    unsetenv("OLD_HOME");
+#endif
+}
+
+struct PibPathConfigFileEmpty2Home
+{
+  const std::string PATH = "build/config-file-empty2-home/";
+};
+
+BOOST_FIXTURE_TEST_CASE(ConstructorEmpty2Config, TestHomeAndPibFixture<PibPathConfigFileEmpty2Home>)
+{
+  createClientConf({"tpm=tpm-memory:"});
+
+  BOOST_REQUIRE_NO_THROW(KeyChain());
+
+  KeyChain keyChain;
+  BOOST_CHECK_EQUAL(keyChain.getPib().getPibLocator(), "pib-sqlite3:");
+  BOOST_CHECK_EQUAL(keyChain.getPib().getTpmLocator(), "tpm-memory:");
+  BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-memory:");
+}
+
+struct PibPathConfigFileMalformedHome
+{
+  const std::string PATH = "build/config-file-malformed-home/";
+};
+
+BOOST_FIXTURE_TEST_CASE(ConstructorMalConfig, TestHomeAndPibFixture<PibPathConfigFileMalformedHome>)
+{
+  createClientConf({"pib=lord", "tpm=ring"});
+
+  BOOST_REQUIRE_THROW(KeyChain(), KeyChain::Error); // Wrong configuration. Error expected.
+}
+
+struct PibPathConfigFileMalformed2Home
+{
+  const std::string PATH = "build/config-file-malformed2-home/";
+};
+
+BOOST_FIXTURE_TEST_CASE(ConstructorMal2Config, TestHomeAndPibFixture<PibPathConfigFileMalformed2Home>)
+{
+  createClientConf({"pib=pib-sqlite3:%PATH%", "tpm=just-wrong"});
+
+  BOOST_REQUIRE_THROW(KeyChain(), KeyChain::Error); // Wrong configuration. Error expected.
+}
+
+struct PibPathConfigFileNonCanonicalTpm
+{
+  const std::string PATH = "build/config-file-non-canonical-tpm/";
+};
+
+BOOST_FIXTURE_TEST_CASE(ConstructorNonCanonicalTpm, TestHomeAndPibFixture<PibPathConfigFileNonCanonicalTpm>) // Bug 4297
+{
+  createClientConf({"pib=pib-sqlite3:", "tpm=tpm-file"});
+
+  {
+    KeyChain keyChain;
+    keyChain.createIdentity("/test");
+    BOOST_CHECK_EQUAL(keyChain.getPib().getPibLocator(), "pib-sqlite3:");
+    BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-file:");
+  }
+
+  {
+    KeyChain keyChain;
+    BOOST_CHECK_EQUAL(keyChain.getPib().getPibLocator(), "pib-sqlite3:");
+    BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-file:");
+    BOOST_CHECK(keyChain.getPib().getIdentities().find("/test") != keyChain.getPib().getIdentities().end());
+  }
+}
+
+BOOST_AUTO_TEST_CASE(KeyChainWithCustomTpmAndPib)
+{
+  BOOST_REQUIRE_NO_THROW((KeyChain("pib-memory", "tpm-memory")));
+  BOOST_REQUIRE_NO_THROW((KeyChain("pib-memory:", "tpm-memory:")));
+  BOOST_REQUIRE_NO_THROW((KeyChain("pib-memory:/something", "tpm-memory:/something")));
+
+  KeyChain keyChain("pib-memory", "tpm-memory");
+  BOOST_CHECK_EQUAL(keyChain.getPib().getPibLocator(), "pib-memory:");
+  BOOST_CHECK_EQUAL(keyChain.getPib().getTpmLocator(), "tpm-memory:");
+  BOOST_CHECK_EQUAL(keyChain.getTpm().getTpmLocator(), "tpm-memory:");
+}
+
+BOOST_FIXTURE_TEST_CASE(SigningWithCorruptedPibTpm, IdentityManagementFixture)
+{
+  Identity id = m_keyChain.createIdentity("/test");
+
+  Data data("/foobar");
+  BOOST_CHECK_NO_THROW(m_keyChain.sign(data, signingByIdentity(id)));
+
+  // now, "corrupting TPM"
+  const_cast<Tpm&>(m_keyChain.getTpm()).deleteKey(id.getDefaultKey().getName());
+
+  BOOST_CHECK_NO_THROW(id.getDefaultKey());
+  BOOST_CHECK_THROW(m_keyChain.sign(data, signingByIdentity(id)), KeyChain::InvalidSigningInfoError);
+}
+
+BOOST_FIXTURE_TEST_CASE(Management, IdentityManagementFixture)
+{
+  Name identityName("/test/id");
+  Name identity2Name("/test/id2");
+
+  BOOST_CHECK_EQUAL(m_keyChain.getPib().getIdentities().size(), 0);
+  BOOST_REQUIRE_THROW(m_keyChain.getPib().getDefaultIdentity(), Pib::Error);
+
+  // Create identity
+  Identity id = m_keyChain.createIdentity(identityName);
+  BOOST_CHECK(id);
+  BOOST_CHECK(m_keyChain.getPib().getIdentities().find(identityName) != m_keyChain.getPib().getIdentities().end());
+  // The first added identity becomes the default identity
+  BOOST_CHECK_NO_THROW(m_keyChain.getPib().getDefaultIdentity());
+  // The default key of the added identity must exist
+  Key key = id.getDefaultKey();
+  // The default certificate of the default key must exist
+  BOOST_CHECK_NO_THROW(key.getDefaultCertificate());
+
+  // Delete key
+  Name key1Name = key.getName();
+  BOOST_CHECK_NO_THROW(id.getKey(key1Name));
+  BOOST_CHECK_EQUAL(id.getKeys().size(), 1);
+  m_keyChain.deleteKey(id, key);
+  // The key instance should not be valid any more
+  BOOST_CHECK(!key);
+  BOOST_CHECK_THROW(id.getKey(key1Name), Pib::Error);
+  BOOST_CHECK_EQUAL(id.getKeys().size(), 0);
+
+  // Create another key
+  m_keyChain.createKey(id);
+  // The added key becomes the default key.
+  Key key2 = id.getDefaultKey();
+  BOOST_REQUIRE(key2);
+  BOOST_CHECK_NE(key2.getName(), key1Name);
+  BOOST_CHECK_EQUAL(id.getKeys().size(), 1);
+  BOOST_CHECK_NO_THROW(key2.getDefaultCertificate());
+
+  // Create the third key
+  Key key3 = m_keyChain.createKey(id);
+  BOOST_CHECK_NE(key3.getName(), key2.getName());
+  // The added key will not be the default key, because the default key already exists
+  BOOST_CHECK_EQUAL(id.getDefaultKey().getName(), key2.getName());
+  BOOST_CHECK_EQUAL(id.getKeys().size(), 2);
+  BOOST_CHECK_NO_THROW(key3.getDefaultCertificate());
+
+  // Delete cert
+  BOOST_CHECK_EQUAL(key3.getCertificates().size(), 1);
+  Certificate key3Cert1 = *key3.getCertificates().begin();
+  Name key3CertName = key3Cert1.getName();
+  m_keyChain.deleteCertificate(key3, key3CertName);
+  BOOST_CHECK_EQUAL(key3.getCertificates().size(), 0);
+  BOOST_REQUIRE_THROW(key3.getDefaultCertificate(), Pib::Error);
+
+  // Add cert
+  m_keyChain.addCertificate(key3, key3Cert1);
+  BOOST_CHECK_EQUAL(key3.getCertificates().size(), 1);
+  BOOST_CHECK_NO_THROW(key3.getDefaultCertificate());
+  m_keyChain.addCertificate(key3, key3Cert1); // overwriting the cert should work
+  BOOST_CHECK_EQUAL(key3.getCertificates().size(), 1);
+  // Add another cert
+  Certificate key3Cert2 = key3Cert1;
+  Name key3Cert2Name = key3.getName();
+  key3Cert2Name.append("Self");
+  key3Cert2Name.appendVersion();
+  key3Cert2.setName(key3Cert2Name);
+  m_keyChain.addCertificate(key3, key3Cert2);
+  BOOST_CHECK_EQUAL(key3.getCertificates().size(), 2);
+
+  // Default certificate setting
+  BOOST_CHECK_EQUAL(key3.getDefaultCertificate().getName(), key3CertName);
+  m_keyChain.setDefaultCertificate(key3, key3Cert2);
+  BOOST_CHECK_EQUAL(key3.getDefaultCertificate().getName(), key3Cert2Name);
+
+  // Default key setting
+  BOOST_CHECK_EQUAL(id.getDefaultKey().getName(), key2.getName());
+  m_keyChain.setDefaultKey(id, key3);
+  BOOST_CHECK_EQUAL(id.getDefaultKey().getName(), key3.getName());
+
+  // Default identity setting
+  Identity id2 = m_keyChain.createIdentity(identity2Name);
+  BOOST_CHECK_EQUAL(m_keyChain.getPib().getDefaultIdentity().getName(), id.getName());
+  m_keyChain.setDefaultIdentity(id2);
+  BOOST_CHECK_EQUAL(m_keyChain.getPib().getDefaultIdentity().getName(), id2.getName());
+
+  // Delete identity
+  m_keyChain.deleteIdentity(id);
+  // The identity instance should not be valid any more
+  BOOST_CHECK(!id);
+  BOOST_REQUIRE_THROW(m_keyChain.getPib().getIdentity(identityName), Pib::Error);
+  BOOST_CHECK(m_keyChain.getPib().getIdentities().find(identityName) == m_keyChain.getPib().getIdentities().end());
+}
+
+BOOST_FIXTURE_TEST_CASE(GeneralSigningInterface, IdentityManagementFixture)
+{
+  Identity id = addIdentity("/id");
+  Key key = id.getDefaultKey();
+  Certificate cert = key.getDefaultCertificate();
+
+  Name hmacKeyName = m_keyChain.createHmacKey();
+  const Tpm& tpm = m_keyChain.getTpm();
+
+  std::vector<SigningInfo> signingInfos = {
+    SigningInfo(),
+
+    SigningInfo(SigningInfo::SIGNER_TYPE_ID, id.getName()),
+    signingByIdentity(id.getName()),
+
+    SigningInfo(id),
+    signingByIdentity(id),
+
+    SigningInfo(SigningInfo::SIGNER_TYPE_KEY, key.getName()),
+    signingByKey(key.getName()),
+
+    SigningInfo(key),
+    signingByKey(key),
+
+    SigningInfo(SigningInfo::SIGNER_TYPE_CERT, cert.getName()),
+    signingByCertificate(cert.getName()),
+    signingByCertificate(cert),
+
+    SigningInfo(SigningInfo::SIGNER_TYPE_HMAC, hmacKeyName),
+    SigningInfo("hmac-sha256:QjM3NEEyNkE3MTQ5MDQzN0FBMDI0RTRGQURENUI0OTdGREZGMUE4RUE2RkYxMkY2RkI2NUFGMjcyMEI1OUNDRg=="),
+
+    SigningInfo(SigningInfo::SIGNER_TYPE_SHA256),
+    signingWithSha256()
+  };
+
+  for (const auto& signingInfo : signingInfos) {
+    BOOST_TEST_MESSAGE("SigningInfo: " << signingInfo);
+    Data data("/data");
+    Interest interest("/interest");
+
+    if (signingInfo.getSignerType() == SigningInfo::SIGNER_TYPE_NULL) {
+      m_keyChain.sign(data);
+      m_keyChain.sign(interest);
+    }
+    else {
+      m_keyChain.sign(data, signingInfo);
+      m_keyChain.sign(interest, signingInfo);
+    }
+
+    Signature interestSignature(interest.getName()[-2].blockFromValue(), interest.getName()[-1].blockFromValue());
+
+    if (signingInfo.getSignerType() == SigningInfo::SIGNER_TYPE_SHA256) {
+      BOOST_CHECK_EQUAL(data.getSignatureType(), tlv::DigestSha256);
+      BOOST_CHECK_EQUAL(interestSignature.getType(), tlv::DigestSha256);
+
+      BOOST_CHECK(verifyDigest(data, DigestAlgorithm::SHA256));
+      BOOST_CHECK(verifyDigest(interest, DigestAlgorithm::SHA256));
+    }
+    else if (signingInfo.getSignerType() == SigningInfo::SIGNER_TYPE_HMAC) {
+      Name keyName = signingInfo.getSignerName();
+      BOOST_CHECK_EQUAL(data.getSignatureType(), tlv::SignatureHmacWithSha256);
+      BOOST_CHECK_EQUAL(interestSignature.getType(), tlv::SignatureHmacWithSha256);
+
+      BOOST_CHECK(bool(verifySignature(data, tpm, keyName, DigestAlgorithm::SHA256)));
+      BOOST_CHECK(bool(verifySignature(interest, tpm, keyName, DigestAlgorithm::SHA256)));
+    }
+    else {
+      BOOST_CHECK_EQUAL(data.getSignatureType(), tlv::SignatureSha256WithEcdsa);
+      BOOST_CHECK_EQUAL(interestSignature.getType(), tlv::SignatureSha256WithEcdsa);
+
+      BOOST_CHECK_EQUAL(data.getKeyLocator()->getName(), cert.getName().getPrefix(-2));
+      BOOST_CHECK_EQUAL(interestSignature.getKeyLocator().getName(), cert.getName().getPrefix(-2));
+
+      BOOST_CHECK(verifySignature(data, key));
+      BOOST_CHECK(verifySignature(interest, key));
+    }
+  }
+}
+
+BOOST_FIXTURE_TEST_CASE(PublicKeySigningDefaults, IdentityManagementFixture)
+{
+  Data data("/test/data");
+
+  // Identity will be created with generated key and self-signed cert with default parameters
+  BOOST_CHECK_THROW(m_keyChain.sign(data, signingByIdentity("/non-existing/identity")), KeyChain::InvalidSigningInfoError);
+
+  // Create identity with EC key and the corresponding self-signed certificate
+  Identity id = addIdentity("/ndn/test/ec", EcKeyParams());
+  BOOST_CHECK_NO_THROW(m_keyChain.sign(data, signingByIdentity(id.getName())));
+  BOOST_CHECK_EQUAL(data.getSignatureType(),
+                    KeyChain::getSignatureType(EcKeyParams().getKeyType(), DigestAlgorithm::SHA256));
+  BOOST_REQUIRE(data.getKeyLocator().has_value());
+  BOOST_CHECK(id.getName().isPrefixOf(data.getKeyLocator()->getName()));
+
+  // Create identity with RSA key and the corresponding self-signed certificate
+  id = addIdentity("/ndn/test/rsa", RsaKeyParams());
+  BOOST_CHECK_NO_THROW(m_keyChain.sign(data, signingByIdentity(id.getName())));
+  BOOST_CHECK_EQUAL(data.getSignatureType(),
+                    KeyChain::getSignatureType(RsaKeyParams().getKeyType(), DigestAlgorithm::SHA256));
+  BOOST_REQUIRE(data.getKeyLocator().has_value());
+  BOOST_CHECK(id.getName().isPrefixOf(data.getKeyLocator()->getName()));
+}
+
+BOOST_FIXTURE_TEST_CASE(ImportPrivateKey, IdentityManagementFixture)
+{
+  Name keyName("/test/device2");
+  std::string rawKey("nPSNOHyZKsg2WLqHAs7MXGb0sjQb4zCT");
+  auto key = make_shared<transform::PrivateKey>();
+  key->loadRaw(KeyType::HMAC, reinterpret_cast<const uint8_t*>(rawKey.data()), rawKey.size());
+
+  m_keyChain.importPrivateKey(keyName, key);
+  BOOST_CHECK_EQUAL(m_keyChain.getTpm().hasKey(keyName), true);
+  BOOST_CHECK_THROW(m_keyChain.importPrivateKey(keyName, key), KeyChain::Error);
+}
+
+BOOST_FIXTURE_TEST_CASE(ExportImport, IdentityManagementFixture)
+{
+  Identity id = addIdentity("/TestKeyChain/ExportIdentity");
+  Certificate cert = id.getDefaultKey().getDefaultCertificate();
+
+  shared_ptr<SafeBag> exported = m_keyChain.exportSafeBag(cert, "1234", 4);
+  Block block = exported->wireEncode();
+
+  m_keyChain.deleteIdentity(id);
+  BOOST_CHECK_THROW(m_keyChain.exportSafeBag(cert, "1234", 4), KeyChain::Error);
+
+  BOOST_CHECK_EQUAL(m_keyChain.getTpm().hasKey(cert.getKeyName()), false);
+  BOOST_CHECK_EQUAL(m_keyChain.getPib().getIdentities().size(), 0);
+
+  SafeBag imported;
+  imported.wireDecode(block);
+  m_keyChain.importSafeBag(imported, "1234", 4);
+  BOOST_CHECK_THROW(m_keyChain.importSafeBag(imported, "1234", 4), KeyChain::Error);
+
+  BOOST_CHECK_EQUAL(m_keyChain.getTpm().hasKey(cert.getKeyName()), true);
+  BOOST_CHECK_EQUAL(m_keyChain.getPib().getIdentities().size(), 1);
+  Identity newId = m_keyChain.getPib().getIdentity(cert.getIdentity());
+  BOOST_CHECK_EQUAL(newId.getKeys().size(), 1);
+  Key newKey = newId.getKey(cert.getKeyName());
+  BOOST_CHECK_EQUAL(newKey.getCertificates().size(), 1);
+  BOOST_CHECK_NO_THROW(newKey.getCertificate(cert.getName()));
+
+  m_keyChain.deleteIdentity(newId);
+  BOOST_CHECK_EQUAL(m_keyChain.getPib().getIdentities().size(), 0);
+  BOOST_CHECK_EQUAL(m_keyChain.getTpm().hasKey(cert.getKeyName()), false);
+}
+
+BOOST_FIXTURE_TEST_CASE(SelfSignedCertValidity, IdentityManagementFixture)
+{
+  Certificate cert = addIdentity("/Security/TestKeyChain/SelfSignedCertValidity")
+                       .getDefaultKey()
+                       .getDefaultCertificate();
+  BOOST_CHECK(cert.isValid());
+  BOOST_CHECK(cert.isValid(time::system_clock::now() + 10 * 365_days));
+  BOOST_CHECK_GT(cert.getValidityPeriod().getPeriod().second, time::system_clock::now() + 10 * 365_days);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // TestKeyChain
+BOOST_AUTO_TEST_SUITE_END() // Security
+
+} // namespace tests
+} // inline namespace v2
+} // namespace security
+} // namespace ndn