diff --git a/src/algo/aes.cpp b/src/algo/aes.cpp
new file mode 100644
index 0000000..07cb788
--- /dev/null
+++ b/src/algo/aes.cpp
@@ -0,0 +1,111 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California
+ *
+ * This file is part of gep (Group-based Encryption Protocol for NDN).
+ * See AUTHORS.md for complete list of gep authors and contributors.
+ *
+ * gep 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.
+ *
+ * gep 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 a copy of the GNU General Public License along with
+ * gep, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ndn-cxx/encoding/buffer-stream.hpp>
+#include "aes.hpp"
+
+namespace ndn {
+namespace gep {
+namespace algo {
+
+using namespace CryptoPP;
+
+Buffer
+crypt(CipherModeBase* cipher, const Buffer& data);
+
+DecryptKey<Aes>
+Aes::generateKey(RandomNumberGenerator& rng, AesKeyParams& params)
+{
+  SecByteBlock key(0x00, params.getKeySize() >> 3);  // Converting key bit-size to byte-size.
+  rng.GenerateBlock(key.data(), key.size());
+
+  DecryptKey<Aes> decryptKey(std::move(Buffer(key.data(), key.size())));
+  return decryptKey;
+}
+
+EncryptKey<Aes>
+Aes::deriveEncryptKey(const Buffer& keyBits)
+{
+  Buffer copy = keyBits;
+  EncryptKey<Aes> encryptKey(std::move(copy));
+  return encryptKey;
+}
+
+Buffer
+Aes::decrypt(const Buffer& keyBits, const Buffer& encryptedData, const EncryptParams& params)
+{
+  switch (params.getEncryptMode()) {
+  case ENCRYPT_MODE_ECB_AES:
+    {
+      ECB_Mode<AES>::Decryption ecbDecryption(keyBits.get(), keyBits.size());
+      return crypt(&ecbDecryption, encryptedData);
+    }
+
+  case ENCRYPT_MODE_CBC_AES:
+    {
+      Buffer initVector = params.getIV();
+      if (initVector.size() != static_cast<size_t>(AES::BLOCKSIZE))
+        throw Error("incorrect initial vector size");
+
+      CBC_Mode<AES>::Decryption cbcDecryption(keyBits.get(), keyBits.size(), initVector.get());
+      return crypt(&cbcDecryption, encryptedData);
+    }
+
+  default:
+    throw Error("unsupported encryption mode");
+  }
+}
+
+Buffer
+Aes::encrypt(const Buffer& keyBits, const Buffer& plainData, const EncryptParams& params)
+{
+  switch (params.getEncryptMode()) {
+  case ENCRYPT_MODE_ECB_AES:
+    {
+      ECB_Mode<AES>::Encryption ecbEncryption(keyBits.get(), keyBits.size());
+      return crypt(&ecbEncryption, plainData);
+    }
+
+  case ENCRYPT_MODE_CBC_AES:
+    {
+      Buffer initVector = params.getIV();
+      if (initVector.size() != static_cast<size_t>(AES::BLOCKSIZE))
+        throw Error("incorrect initial vector size");
+
+      CBC_Mode<AES>::Encryption cbcEncryption(keyBits.get(), keyBits.size(), initVector.get());
+      return crypt(&cbcEncryption, plainData);
+    }
+
+  default:
+    throw Error("unsupported encryption mode");
+  }
+}
+
+Buffer
+crypt(CipherModeBase* cipher, const Buffer& data)
+{
+  OBufferStream obuf;
+  StringSource pipe(data.get(), data.size(), true,
+                    new StreamTransformationFilter(*cipher, new FileSink(obuf)));
+  return *(obuf.buf());
+}
+
+} // namespace algo
+} // namespace gep
+} // namespace ndn