diff --git a/tests/unit-tests/challenge-possession.t.cpp b/tests/unit-tests/challenge-possession.t.cpp
new file mode 100644
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--- /dev/null
+++ b/tests/unit-tests/challenge-possession.t.cpp
@@ -0,0 +1,151 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2017-2020, Regents of the University of California.
+ *
+ * This file is part of ndncert, a certificate management system based on NDN.
+ *
+ * ndncert is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ndncert 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 General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License along with
+ * ndncert, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndncert authors and contributors.
+ */
+
+#include "challenge/challenge-possession.hpp"
+#include "test-common.hpp"
+#include "detail/challenge-encoder.hpp"
+
+namespace ndn {
+namespace ndncert {
+namespace tests {
+
+BOOST_FIXTURE_TEST_SUITE(TestChallengeCredential, IdentityManagementFixture)
+
+BOOST_AUTO_TEST_CASE(LoadConfig)
+{
+  ChallengePossession challenge("./tests/unit-tests/config-files/config-challenge-possession");
+  BOOST_CHECK_EQUAL(challenge.CHALLENGE_TYPE, "Possession");
+
+  challenge.parseConfigFile();
+  BOOST_CHECK_EQUAL(challenge.m_trustAnchors.size(), 1);
+  auto cert = challenge.m_trustAnchors.front();
+  BOOST_CHECK_EQUAL(cert.getName(),
+                    "/ndn/site1/KEY/%11%BC%22%F4c%15%FF%17/self/%FD%00%00%01Y%C8%14%D9%A5");
+}
+
+BOOST_AUTO_TEST_CASE(HandleChallengeRequest)
+{
+  // create trust anchor
+  ChallengePossession challenge("./tests/unit-tests/config-files/config-challenge-possession");
+  auto identity = addIdentity(Name("/trust"));
+  auto key = identity.getDefaultKey();
+  auto trustAnchor = key.getDefaultCertificate();
+  challenge.parseConfigFile();
+  challenge.m_trustAnchors.front() = trustAnchor;
+
+  // create certificate request
+  auto identityA = addIdentity(Name("/example"));
+  auto keyA = identityA.getDefaultKey();
+  auto certA = key.getDefaultCertificate();
+  RequestId requestId = {{101}};
+  ca::RequestState state;
+  state.caPrefix = Name("/example");
+  state.requestId = requestId;
+  state.requestType = RequestType::NEW;
+  state.cert = certA;
+
+  // create requester's credential
+  auto identityB = addIdentity(Name("/trust/cert"));
+  auto keyB = identityB.getDefaultKey();
+  auto credentialName = Name(keyB.getName()).append("Credential").appendVersion();
+  security::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)));
+  m_keyChain.sign(credential, signingByCertificate(trustAnchor).setSignatureInfo(signatureInfo));
+  m_keyChain.addCertificate(keyB, credential);
+
+  // using private key to sign cert request
+  auto params = challenge.getRequestedParameterList(state.status, "");
+  ChallengePossession::fulfillParameters(params, m_keyChain, credential.getName(), std::array<uint8_t, 16>{});
+  Block paramsTlv = challenge.genChallengeRequestTLV(state.status, "", params);
+  challenge.handleChallengeRequest(paramsTlv, state);
+  BOOST_CHECK_EQUAL(statusToString(state.status), statusToString(Status::CHALLENGE));
+  BOOST_CHECK_EQUAL(state.challengeState->challengeStatus, "need-proof");
+
+  // reply from server
+  auto nonceBuf = 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);
+  ChallengePossession::fulfillParameters(params2, m_keyChain, credential.getName(), nonce);
+  Block paramsTlv2 = challenge.genChallengeRequestTLV(state.status, state.challengeState->challengeStatus, params2);
+  challenge.handleChallengeRequest(paramsTlv2, state);
+  BOOST_CHECK_EQUAL(statusToString(state.status), statusToString(Status::PENDING));
+}
+
+BOOST_AUTO_TEST_CASE(HandleChallengeRequestProofFail)
+{
+  // create trust anchor
+  ChallengePossession challenge("./tests/unit-tests/config-files/config-challenge-possession");
+  auto identity = addIdentity(Name("/trust"));
+  auto key = identity.getDefaultKey();
+  auto trustAnchor = key.getDefaultCertificate();
+  challenge.parseConfigFile();
+  challenge.m_trustAnchors.front() = trustAnchor;
+
+  // create certificate request
+  auto identityA = addIdentity(Name("/example"));
+  auto keyA = identityA.getDefaultKey();
+  auto certA = key.getDefaultCertificate();
+  RequestId requestId = {{101}};
+  ca::RequestState state;
+  state.caPrefix = Name("/example");
+  state.requestId = requestId;
+  state.requestType = RequestType::NEW;
+  state.cert = certA;
+
+  // create requester's credential
+  auto identityB = addIdentity(Name("/trust/cert"));
+  auto keyB = identityB.getDefaultKey();
+  auto credentialName = Name(keyB.getName()).append("Credential").appendVersion();
+  security::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)));
+  m_keyChain.sign(credential, signingByCertificate(trustAnchor).setSignatureInfo(signatureInfo));
+  m_keyChain.addCertificate(keyB, credential);
+
+  // using private key to sign cert request
+  auto params = challenge.getRequestedParameterList(state.status, "");
+  ChallengePossession::fulfillParameters(params, m_keyChain, credential.getName(), std::array<uint8_t, 16>{});
+  Block paramsTlv = challenge.genChallengeRequestTLV(state.status, "", params);
+  challenge.handleChallengeRequest(paramsTlv, state);
+  BOOST_CHECK_EQUAL(statusToString(state.status), statusToString(Status::CHALLENGE));
+  BOOST_CHECK_EQUAL(state.challengeState->challengeStatus, "need-proof");
+
+  // reply from server
+  std::array<uint8_t, 16> nonce{};
+  auto params2 = challenge.getRequestedParameterList(state.status, state.challengeState->challengeStatus);
+  ChallengePossession::fulfillParameters(params2, m_keyChain, credential.getName(), nonce);
+  Block paramsTlv2 = challenge.genChallengeRequestTLV(state.status, state.challengeState->challengeStatus, params2);
+  challenge.handleChallengeRequest(paramsTlv2, state);
+  BOOST_CHECK_EQUAL(statusToString(state.status), statusToString(Status::FAILURE));
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+} // namespace tests
+} // namespace ndncert
+} // namespace ndn