diff --git a/tests/unit-tests/ca-memory.t.cpp b/tests/unit-tests/ca-memory.t.cpp
index 7425a0e..a1bcd28 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) 2017-2019, 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.
  *
@@ -82,7 +82,7 @@
   auto cert1 = key1.getDefaultCertificate();
 
   // add operation
-  CertificateRequest request1(Name("/ndn/site1"), "123", STATUS_BEFORE_CHALLENGE, cert1);
+  CertificateRequest request1(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert1);
   BOOST_CHECK_NO_THROW(storage.addRequest(request1));
 
   // get operation
@@ -95,7 +95,7 @@
   json.put("code", "1234");
 
   // update operation
-  CertificateRequest request2(Name("/ndn/site1"), "123", STATUS_CHALLENGE, CHALLENGE_STATUS_SUCCESS,
+  CertificateRequest request2(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_CHALLENGE, CHALLENGE_STATUS_SUCCESS,
                              "Email", time::toIsoString(time::system_clock::now()), 3600, 3, json, cert1);
   storage.updateRequest(request2);
   result = storage.getRequest("123");
@@ -106,7 +106,7 @@
   auto identity2 = addIdentity(Name("/ndn/site2"));
   auto key2 = identity2.getDefaultKey();
   auto cert2 = key2.getDefaultCertificate();
-  CertificateRequest request3(Name("/ndn/site2"), "456", STATUS_BEFORE_CHALLENGE, cert2);
+  CertificateRequest request3(Name("/ndn/site2"), "456", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert2);
   storage.addRequest(request3);
 
   // list operation
diff --git a/tests/unit-tests/ca-module.t.cpp b/tests/unit-tests/ca-module.t.cpp
index cb3cfcd..64a5d7f 100644
--- a/tests/unit-tests/ca-module.t.cpp
+++ b/tests/unit-tests/ca-module.t.cpp
@@ -46,7 +46,7 @@
 
   advanceClocks(time::milliseconds(20), 60);
   BOOST_CHECK_EQUAL(ca.m_registeredPrefixHandles.size(), 2);
-  BOOST_CHECK_EQUAL(ca.m_interestFilterHandles.size(), 4);  // onInfo, onProbe, onNew, onChallenge
+  BOOST_CHECK_EQUAL(ca.m_interestFilterHandles.size(), 5); // onInfo, onProbe, onNew, onChallenge, onRevoke
 }
 
 BOOST_AUTO_TEST_CASE(HandleProbe)
@@ -367,7 +367,112 @@
   BOOST_CHECK_EQUAL(count, 3);
 }
 
-BOOST_AUTO_TEST_SUITE_END()  // TestCaModule
+BOOST_AUTO_TEST_CASE(HandleRevoke)
+{
+  auto identity = addIdentity(Name("/ndn"));
+  auto key = identity.getDefaultKey();
+  auto cert = key.getDefaultCertificate();
+
+  util::DummyClientFace face(io, { true, true });
+  CaModule ca(face, m_keyChain, "tests/unit-tests/ca.conf.test", "ca-storage-memory");
+  advanceClocks(time::milliseconds(20), 60);
+
+  //generate a certificate
+  auto clientIdentity = m_keyChain.createIdentity("/ndn/qwerty");
+  auto clientKey = clientIdentity.getDefaultKey();
+  security::v2::Certificate clientCert;
+  clientCert.setName(Name(clientKey.getName()).append("cert-request").appendVersion());
+  clientCert.setContentType(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)));
+  m_keyChain.sign(clientCert, signingByKey(clientKey.getName()).setSignatureInfo(signatureInfo));
+  CertificateRequest certRequest(Name("/ndn"), "122", REQUEST_TYPE_NEW, STATUS_SUCCESS, clientCert);
+  auto issuedCert = ca.issueCertificate(certRequest);
+
+  ClientModule client(m_keyChain);
+  ClientCaItem item;
+  item.m_caName = Name("/ndn");
+  item.m_anchor = cert;
+  client.getClientConf().m_caItems.push_back(item);
+
+  auto interest = client.generateRevokeInterest(issuedCert);
+
+  int count = 0;
+  face.onSendData.connect([&] (const Data& response) {
+    count++;
+    BOOST_CHECK(security::verifySignature(response, cert));
+    auto contentBlock = response.getContent();
+    contentBlock.parse();
+
+    BOOST_CHECK(readString(contentBlock.get(tlv_ecdh_pub)) != "");
+    BOOST_CHECK(readString(contentBlock.get(tlv_salt)) != "");
+    BOOST_CHECK(readString(contentBlock.get(tlv_request_id)) != "");
+
+    auto challengeBlockCount = 0;
+    for (auto const& element : contentBlock.elements()) {
+        if (element.type() == tlv_challenge) {
+            challengeBlockCount++;
+        }
+    }
+
+    BOOST_CHECK(challengeBlockCount != 0);
+
+    client.onRevokeResponse(response);
+    BOOST_CHECK_EQUAL_COLLECTIONS(client.m_aesKey, client.m_aesKey + sizeof(client.m_aesKey),
+            ca.m_aesKey, ca.m_aesKey + sizeof(ca.m_aesKey));
+  });
+  face.receive(*interest);
+
+  advanceClocks(time::milliseconds(20), 60);
+  BOOST_CHECK_EQUAL(count, 1);
+}
+
+BOOST_AUTO_TEST_CASE(HandleRevokeWithBadCert)
+{
+  auto identity = addIdentity(Name("/ndn"));
+  auto key = identity.getDefaultKey();
+  auto cert = key.getDefaultCertificate();
+
+  util::DummyClientFace face(io, { true, true });
+  CaModule ca(face, m_keyChain, "tests/unit-tests/ca.conf.test", "ca-storage-memory");
+  advanceClocks(time::milliseconds(20), 60);
+
+  //generate a certificate
+  auto clientIdentity = m_keyChain.createIdentity("/ndn/qwerty");
+  auto clientKey = clientIdentity.getDefaultKey();
+  security::v2::Certificate clientCert;
+  clientCert.setName(Name(clientKey.getName()).append("NDNCERT").append(std::to_string(1473283247810732701)));
+  clientCert.setContentType(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)));
+  m_keyChain.sign(clientCert, signingByKey(clientKey.getName()).setSignatureInfo(signatureInfo));
+
+  ClientModule client(m_keyChain);
+  ClientCaItem item;
+  item.m_caName = Name("/ndn");
+  item.m_anchor = cert;
+  client.getClientConf().m_caItems.push_back(item);
+
+  auto interest = client.generateRevokeInterest(clientCert);
+
+  int count = 0;
+  face.onSendData.connect([&] (const Data& response) {
+    count++;
+  });
+  face.receive(*interest);
+
+  advanceClocks(time::milliseconds(20), 60);
+  BOOST_CHECK_EQUAL(count, 0);
+}
+
+
+BOOST_AUTO_TEST_SUITE_END() // TestCaModule
 
 }  // namespace tests
 }  // namespace ndncert
diff --git a/tests/unit-tests/ca-sqlite.t.cpp b/tests/unit-tests/ca-sqlite.t.cpp
index 07782a6..aa70f3a 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) 2017-2019, 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.
  *
@@ -81,7 +81,7 @@
   auto cert1 = key1.getDefaultCertificate();
 
   // add operation
-  CertificateRequest request1(Name("/ndn/site1"), "123", STATUS_BEFORE_CHALLENGE, cert1);
+  CertificateRequest request1(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert1);
   BOOST_CHECK_NO_THROW(storage.addRequest(request1));
 
   // get operation
@@ -93,7 +93,7 @@
   // update operation
   JsonSection json;
   json.put("test", "4567");
-  CertificateRequest request2(Name("/ndn/site1"), "123", STATUS_CHALLENGE, CHALLENGE_STATUS_SUCCESS,
+  CertificateRequest request2(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_CHALLENGE, CHALLENGE_STATUS_SUCCESS,
                              "Email", time::toIsoString(time::system_clock::now()), 3600, 3, json, cert1);
   storage.updateRequest(request2);
   result = storage.getRequest("123");
@@ -104,7 +104,7 @@
   auto identity2 = addIdentity(Name("/ndn/site2"));
   auto key2 = identity2.getDefaultKey();
   auto cert2 = key2.getDefaultCertificate();
-  CertificateRequest request3(Name("/ndn/site2"), "456", STATUS_BEFORE_CHALLENGE, cert2);
+  CertificateRequest request3(Name("/ndn/site2"), "456", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert2);
   storage.addRequest(request3);
 
   // list operation
diff --git a/tests/unit-tests/challenge-credential.t.cpp b/tests/unit-tests/challenge-credential.t.cpp
index 2b8e9b2..3472687 100644
--- a/tests/unit-tests/challenge-credential.t.cpp
+++ b/tests/unit-tests/challenge-credential.t.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.
  *
@@ -55,7 +55,7 @@
   auto identityA = addIdentity(Name("/example"));
   auto keyA = identityA.getDefaultKey();
   auto certA = key.getDefaultCertificate();
-  CertificateRequest request(Name("/example"), "123", STATUS_BEFORE_CHALLENGE, certA);
+  CertificateRequest request(Name("/example"), "123", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, certA);
 
   // create requester's existing cert
   auto identityB = addIdentity(Name("/trust/cert"));
diff --git a/tests/unit-tests/challenge-email.t.cpp b/tests/unit-tests/challenge-email.t.cpp
index 8ff47c4..50e30c5 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) 2017-2019, 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.
  *
@@ -45,7 +45,7 @@
   auto identity = addIdentity(Name("/ndn/site1"));
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_BEFORE_CHALLENGE, cert);
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert);
 
   Block paramTLV = makeEmptyBlock(tlv_encrypted_payload);
   paramTLV.push_back(makeStringBlock(tlv_parameter_key, ChallengeEmail::JSON_EMAIL));
@@ -95,7 +95,7 @@
   auto identity = addIdentity(Name("/ndn/site1"));
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_BEFORE_CHALLENGE, cert);
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert);
 
   Block paramTLV = makeEmptyBlock(tlv_encrypted_payload);
   paramTLV.push_back(makeStringBlock(tlv_parameter_key, ChallengeEmail::JSON_EMAIL));
@@ -115,7 +115,7 @@
   auto cert = key.getDefaultCertificate();
   JsonSection json;
   json.put(ChallengeEmail::JSON_CODE, "4567");
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_CHALLENGE, ChallengeEmail::NEED_CODE,
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_CHALLENGE, ChallengeEmail::NEED_CODE,
                              "Email", time::toIsoString(time::system_clock::now()), 3600, 3, json, cert);
 
   Block paramTLV = makeEmptyBlock(tlv_encrypted_payload);
@@ -137,7 +137,7 @@
   auto cert = key.getDefaultCertificate();
   JsonSection json;
   json.put(ChallengeEmail::JSON_CODE, "4567");
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_CHALLENGE, ChallengeEmail::NEED_CODE,
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_CHALLENGE, ChallengeEmail::NEED_CODE,
                              "email", time::toIsoString(time::system_clock::now()), 3600, 3, json, cert);
 
   Block paramTLV = makeEmptyBlock(tlv_encrypted_payload);
diff --git a/tests/unit-tests/challenge-pin.t.cpp b/tests/unit-tests/challenge-pin.t.cpp
index a1fea0d..9cabf38 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) 2017-2019, 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 @@
   auto identity = addIdentity(Name("/ndn/site1"));
   auto key = identity.getDefaultKey();
   auto cert = key.getDefaultCertificate();
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_BEFORE_CHALLENGE, cert);
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_BEFORE_CHALLENGE, cert);
 
   ChallengePin challenge;
   challenge.handleChallengeRequest(makeEmptyBlock(tlv_encrypted_payload), request);
@@ -55,7 +55,7 @@
   auto cert = key.getDefaultCertificate();
   JsonSection secret;
   secret.add(ChallengePin::JSON_PIN_CODE, "12345");
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_CHALLENGE, ChallengePin::NEED_CODE, "pin",
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_CHALLENGE, ChallengePin::NEED_CODE, "pin",
                              time::toIsoString(time::system_clock::now()), 3600, 3, secret, cert);
 
   Block paramTLV = makeEmptyBlock(tlv_encrypted_payload);
@@ -77,7 +77,7 @@
   auto cert = key.getDefaultCertificate();
   JsonSection secret;
   secret.add(ChallengePin::JSON_PIN_CODE, "12345");
-  CertificateRequest request(Name("/ndn/site1"), "123", STATUS_CHALLENGE, ChallengePin::NEED_CODE, "pin",
+  CertificateRequest request(Name("/ndn/site1"), "123", REQUEST_TYPE_NEW, STATUS_CHALLENGE, ChallengePin::NEED_CODE, "pin",
                              time::toIsoString(time::system_clock::now()), 3600, 3, secret, cert);
 
   Block paramTLV = makeEmptyBlock(tlv_encrypted_payload);