diff --git a/src/crypto-support/enc-tlv.cpp b/src/crypto-support/enc-tlv.cpp
new file mode 100644
index 0000000..8260957
--- /dev/null
+++ b/src/crypto-support/enc-tlv.cpp
@@ -0,0 +1,78 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2017-2019, 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.
+ */
+
+#include "enc-tlv.hpp"
+#include "crypto-helper.hpp"
+#include <ndn-cxx/util/random.hpp>
+#include <ndn-cxx/security/transform/stream-sink.hpp>
+#include <ndn-cxx/encoding/buffer-stream.hpp>
+#include <ndn-cxx/security/transform/buffer-source.hpp>
+#include <ndn-cxx/security/transform/block-cipher.hpp>
+
+namespace ndn {
+namespace ndncert {
+
+const size_t DEFAULT_IV_SIZE = 16;
+
+Block
+genEncBlock(uint32_t tlv_type, const uint8_t* key, size_t keyLen, const uint8_t* payload, size_t payloadSize)
+{
+  Buffer iv;
+  iv.resize(DEFAULT_IV_SIZE);
+  random::generateSecureBytes(iv.data(), iv.size());
+
+  OBufferStream os;
+  security::transform::bufferSource(payload, payloadSize)
+    >> security::transform::blockCipher(BlockCipherAlgorithm::AES_CBC,
+                                        CipherOperator::ENCRYPT,
+                                        key, keyLen, iv.data(), iv.size())
+    >> security::transform::streamSink(os);
+    auto encryptedPayload = *os.buf();
+
+  // create the content block
+  auto content = makeEmptyBlock(tlv_type);
+  content.push_back(makeBinaryBlock(ENCRYPTED_PAYLOAD, encryptedPayload.data(), encryptedPayload.size()));
+  content.push_back(makeBinaryBlock(INITIAL_VECTOR, iv.data(), iv.size()));
+  content.encode();
+  return content;
+}
+
+Buffer
+parseEncBlock(const uint8_t* key, size_t keyLen, const Block& block)
+{
+  block.parse();
+  Buffer iv(block.get(INITIAL_VECTOR).value(),
+            block.get(INITIAL_VECTOR).value_size());
+  Buffer encryptedPayload(block.get(ENCRYPTED_PAYLOAD).value(),
+                          block.get(ENCRYPTED_PAYLOAD).value_size());
+
+  OBufferStream os;
+  security::transform::bufferSource(encryptedPayload.data(), encryptedPayload.size())
+    >> security::transform::blockCipher(BlockCipherAlgorithm::AES_CBC,
+                                        CipherOperator::DECRYPT,
+                                        key, keyLen, iv.data(), iv.size())
+    >> security::transform::streamSink(os);
+
+  auto payload = *os.buf();
+  return payload;
+}
+
+} // namespace ndncert
+} // namespace ndn