diff --git a/src/certificate-request.hpp b/src/certificate-request.hpp
new file mode 100644
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--- /dev/null
+++ b/src/certificate-request.hpp
@@ -0,0 +1,177 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2017, 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.
+ */
+
+#ifndef NDNCERT_CERTFICATE_REQUEST_HPP
+#define NDNCERT_CERTFICATE_REQUEST_HPP
+
+#include "ndncert-common.hpp"
+#include <ndn-cxx/security/v2/certificate.hpp>
+
+namespace ndn {
+namespace ndncert {
+
+/**
+ * @brief Represents a certificate request instance.
+ *
+ * ChallengeModule should take use of m_challengeStatus, m_challengeInstruction and
+ * m_challengeDefinedField to finish verification.
+ *
+ */
+class CertificateRequest
+{
+public:
+  enum ApplicationStatus {
+    Pending = 0,
+    Verifying = 1,
+    Success = 2,
+    Failure = 3
+  };
+
+public:
+  CertificateRequest(const Name& caName, const std::string& requestId,
+                     const security::v2::Certificate& cert);
+
+  CertificateRequest(const Name& caName, const std::string& requestId,
+                     const ApplicationStatus& status, const std::string& challengeType,
+                     const std::string& challengeStatus, const std::string& challengeDefinedField,
+                     const security::v2::Certificate& certBlock);
+
+  const Name&
+  getCaName() const
+  {
+    return m_caName;
+  }
+
+  const std::string&
+  getRequestId() const
+  {
+    return m_requestId;
+  }
+
+  const ApplicationStatus&
+  getStatus() const
+  {
+    return m_status;
+  }
+
+  const std::string&
+  getChallengeType() const
+  {
+    return m_challengeType;
+  }
+
+  const std::string&
+  getChallengeDefinedField() const
+  {
+    return m_challengeDefinedField;
+  }
+
+  const std::string&
+  getChallengeInstruction() const
+  {
+    return m_challengeInstruction;
+  }
+
+  const std::string&
+  getChallengeStatus() const
+  {
+    return m_challengeStatus;
+  }
+
+  const security::v2::Certificate&
+  getCert() const
+  {
+    return m_cert;
+  }
+
+  /**
+   * These setters should only be invoked by ChallengeModule
+   */
+  void
+  setStatus(const ApplicationStatus& status)
+  {
+    m_status = status;
+  }
+
+  void
+  setChallengeType(const std::string& challengeType)
+  {
+    m_challengeType = challengeType;
+  }
+
+  void
+  setChallengeStatus(const std::string& challengeStatus)
+  {
+    m_challengeStatus = challengeStatus;
+  }
+
+  void
+  setChallengeDefinedField(const std::string& challengeDefinedField)
+  {
+    m_challengeDefinedField = challengeDefinedField;
+  }
+
+  void
+  setChallengeInstruction(const std::string& challengeInstruction)
+  {
+    m_challengeInstruction = challengeInstruction;
+  }
+
+private:
+  Name m_caName;
+  std::string m_requestId;
+  ApplicationStatus m_status;
+  std::string m_challengeType;
+
+  /**
+   * @brief Defined by ChallengeModule to indicate the verification status.
+   *
+   * This field will be stored by CA.
+   */
+  std::string m_challengeStatus;
+
+  /**
+   * @brief Defined by ChallengeModule to store secret information.
+   *
+   * This field will be stored by CA.
+   */
+  std::string m_challengeDefinedField;
+
+  /**
+   * @brief Defined by ChallengeModule to indicate end entity the next step.
+   *
+   * This field will be presented to end entity.
+   * This field will NOT be stored by CA.
+   */
+  std::string m_challengeInstruction;
+
+  security::v2::Certificate m_cert;
+};
+
+std::ostream&
+operator<<(std::ostream& os, CertificateRequest::ApplicationStatus status);
+
+std::ostream&
+operator<<(std::ostream& os, const CertificateRequest& request);
+
+} // namespace ndncert
+} // namespace ndn
+
+#endif // NDNCERT_CERTFICATE_REQUEST_HPP