diff --git a/ndn-cpp/security/certificate/public-key.cpp b/ndn-cpp/security/certificate/public-key.cpp
new file mode 100644
index 0000000..1f64c07
--- /dev/null
+++ b/ndn-cpp/security/certificate/public-key.cpp
@@ -0,0 +1,57 @@
+/* -*- 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.
+ */
+
+#include "../security-exception.hpp"
+#include "../../c/util/crypto.h"
+#include "public-key.hpp"
+
+using namespace std;
+using namespace ndn::ptr_lib;
+
+namespace ndn {
+
+#if 0
+Ptr<der::DerNode>
+PublicKey::toDER()
+{
+  boost::iostreams::stream
+    <boost::iostreams::array_source> is (m_key.buf (), m_key.size ());
+
+  return der::DerNode::parse(reinterpret_cast<InputIterator &> (is));
+}
+#endif
+
+static int RSA_OID[] = { 1, 2, 840, 113549, 1, 1, 1 };
+
+shared_ptr<PublicKey>
+PublicKey::fromDer(const Blob& keyDer)
+{
+  // Use a temporary pointer since d2i updates it.
+  const unsigned char *derPointer = keyDer.buf();
+  RSA *publicKey = d2i_RSA_PUBKEY(NULL, &derPointer, keyDer.size());
+  if (!publicKey)
+    throw UnrecognizedKeyFormatException("Error decoding public key DER");  
+  RSA_free(publicKey);
+  
+  return shared_ptr<PublicKey>(new PublicKey(OID(vector<int>(RSA_OID, RSA_OID + sizeof(RSA_OID))), keyDer));
+}
+
+Blob
+PublicKey::getDigest(DigestAlgorithm digestAlgorithm) const
+{
+  if (digestAlgorithm == DIGEST_ALGORITHM_SHA256) {
+    unsigned char digest[SHA256_DIGEST_LENGTH];
+    ndn_digestSha256(keyDer_.buf(), keyDer_.size(), digest);
+    
+    return Blob(digest, sizeof(digest));
+  }
+  else
+    throw UnrecognizedDigestAlgorithmException("Wrong format!");
+}
+
+}