diff --git a/src/security/security-common.cpp b/src/security/security-common.cpp
new file mode 100644
index 0000000..0f8714d
--- /dev/null
+++ b/src/security/security-common.cpp
@@ -0,0 +1,127 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library 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 Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "security-common.hpp"
+#include <ostream>
+
+namespace ndn {
+
+std::ostream&
+operator<<(std::ostream& os, KeyType keyType)
+{
+  switch (keyType) {
+  case KeyType::NONE:
+    os << "NONE";
+    break;
+  case KeyType::RSA:
+    os << "RSA";
+    break;
+  case KeyType::EC:
+    os << "EC";
+    break;
+  case KeyType::AES:
+    os << "AES";
+    break;
+  default:
+    os << static_cast<int>(keyType);
+    break;
+  };
+  return os;
+}
+
+std::ostream&
+operator<<(std::ostream& os, KeyClass keyClass)
+{
+  switch (keyClass) {
+  case KeyClass::NONE:
+    os << "NONE";
+    break;
+  case KeyClass::PUBLIC:
+    os << "PUBLIC";
+    break;
+  case KeyClass::PRIVATE:
+    os << "PRIVATE";
+    break;
+  case KeyClass::SYMMETRIC:
+    os << "SYMMETRIC";
+    break;
+  default:
+    os << static_cast<int>(keyClass);
+    break;
+  };
+  return os;
+}
+
+std::ostream&
+operator<<(std::ostream& os, DigestAlgorithm algorithm)
+{
+  switch (algorithm) {
+  case DigestAlgorithm::NONE:
+    os << "NONE";
+    break;
+  case DigestAlgorithm::SHA256:
+    os << "SHA256";
+    break;
+  default:
+    os << static_cast<int>(algorithm);
+    break;
+  };
+  return os;
+}
+
+std::ostream&
+operator<<(std::ostream& os, BlockCipherAlgorithm algorithm)
+{
+  switch (algorithm) {
+  case BlockCipherAlgorithm::NONE:
+    os << "NONE";
+    break;
+  case BlockCipherAlgorithm::AES_CBC:
+    os << "AES_CBC";
+    break;
+  default:
+    os << static_cast<int>(algorithm);
+    break;
+  };
+  return os;
+}
+
+std::ostream&
+operator<<(std::ostream& os, AclType aclType)
+{
+  switch (aclType) {
+  case AclType::NONE:
+    os << "NONE";
+    break;
+  case AclType::PUBLIC:
+    os << "PUBLIC";
+    break;
+  case AclType::PRIVATE:
+    os << "PRIVATE";
+    break;
+  default:
+    os << static_cast<int>(aclType);
+    break;
+  };
+  return os;
+}
+
+} // namespace ndn