diff --git a/include/ndn-cpp/security/certificate.hpp b/include/ndn-cpp/security/certificate.hpp
new file mode 100644
index 0000000..9871733
--- /dev/null
+++ b/include/ndn-cpp/security/certificate.hpp
@@ -0,0 +1,156 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/**
+ * Copyright (C) 2013 Regents of the University of California.
+ * @author: Yingdi Yu <yingdi@cs.ucla.edu>
+ * @author: Jeff Thompson <jefft0@remap.ucla.edu>
+ * See COPYING for copyright and distribution information.
+ */
+
+#ifndef NDN_CERTIFICATE_HPP
+#define NDN_CERTIFICATE_HPP
+
+#include "../data.hpp"
+#include "../common.hpp"
+
+#include "certificate-subject-description.hpp"
+#include "certificate-extension.hpp"
+#include "public-key.hpp"
+
+namespace ndn {
+
+class Certificate : public Data {
+public:
+  struct Error : public std::runtime_error { Error(const std::string &what) : std::runtime_error(what) {} };
+
+  typedef std::vector<CertificateSubjectDescription> SubjectDescriptionList;
+  typedef std::vector<CertificateExtension> ExtensionList;
+
+  /**
+   * The default constructor.
+   */
+  Certificate();
+
+  /**
+   * Create a Certificate from the content in the data packet.
+   * @param data The data packet with the content to decode.
+   */
+  Certificate(const Data& data);
+ 
+  /**
+   * The virtual destructor.
+   */
+  virtual 
+  ~Certificate();
+
+  inline void
+  wireDecode(const Block &wire);
+  
+  /**
+   * encode certificate info into content
+   */
+  void
+  encode();
+
+  /**
+   * Add a subject description.
+   * @param description The description to be added.
+   */
+  void 
+  addSubjectDescription(const CertificateSubjectDescription& description) { subjectDescriptionList_.push_back(description); }
+
+  const SubjectDescriptionList& 
+  getSubjectDescriptionList() const { return subjectDescriptionList_; }
+  
+  SubjectDescriptionList& 
+  getSubjectDescriptionList() { return subjectDescriptionList_; }
+ 
+  /**
+   * Add a certificate extension.
+   * @param extension the extension to be added
+   */
+  void 
+  addExtension(const CertificateExtension& extension) { extensionList_.push_back(extension); }
+
+  const ExtensionList&
+  getExtensionList() const { return extensionList_; }
+  
+  ExtensionList&
+  getExtensionList() { return extensionList_; }
+
+  void 
+  setNotBefore(const MillisecondsSince1970& notBefore) { notBefore_ = notBefore; }
+
+  MillisecondsSince1970& 
+  getNotBefore() { return notBefore_; }
+  
+  const MillisecondsSince1970& 
+  getNotBefore() const { return notBefore_; }
+
+  void
+  setNotAfter(const MillisecondsSince1970& notAfter) { notAfter_ = notAfter; }
+
+  MillisecondsSince1970& 
+  getNotAfter() { return notAfter_; }
+
+  const MillisecondsSince1970& 
+  getNotAfter() const { return notAfter_; }
+
+  void
+  setPublicKeyInfo(const PublicKey& key) { key_ = key; }
+  
+  PublicKey& 
+  getPublicKeyInfo() { return key_; }
+
+  const PublicKey& 
+  getPublicKeyInfo() const { return key_; }
+
+  // virtual Name 
+  // getPublicKeyName() const = 0;
+  
+  /**
+   * Check if the certificate is valid.
+   * @return True if the current time is earlier than notBefore.
+   */
+  bool 
+  isTooEarly();
+
+  /**
+   * Check if the certificate is valid.
+   * @return True if the current time is later than notAfter.
+   */
+  bool
+  isTooLate();
+
+  void 
+  printCertificate(std::ostream &os) const;
+
+protected:
+  void
+  decode();
+
+protected:
+  SubjectDescriptionList subjectDescriptionList_;
+  MillisecondsSince1970 notBefore_;
+  MillisecondsSince1970 notAfter_;
+  PublicKey key_;
+  ExtensionList extensionList_;
+};
+
+inline void
+Certificate::wireDecode(const Block &wire)
+{
+  Data::wireDecode(wire);
+  decode();
+}
+
+
+inline std::ostream&
+operator <<(std::ostream &os, const Certificate &cert)
+{
+  cert.printCertificate(os);
+  return os;
+}
+
+} // namespace ndn
+
+#endif