diff --git a/src/security/transform/hex-decode.hpp b/src/security/transform/hex-decode.hpp
new file mode 100644
index 0000000..77d477d
--- /dev/null
+++ b/src/security/transform/hex-decode.hpp
@@ -0,0 +1,80 @@
+/* -*- 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.
+ */
+
+#ifndef NDN_CXX_SECURITY_TRANSFORM_HEX_DECODE_HPP
+#define NDN_CXX_SECURITY_TRANSFORM_HEX_DECODE_HPP
+
+#include "transform-base.hpp"
+
+namespace ndn {
+namespace security {
+namespace transform {
+
+/**
+ * @brief The module to perform hexadecimal decoding transformation.
+ *
+ * For example, if the input is a string "012345", the output will be
+ * a byte stream: 0x01, 0x23, 0x45.
+ *
+ * If the total length of input is not even (2n + 1), the module will throw Error.
+ */
+class HexDecode : public Transform
+{
+public:
+  /**
+   * @brief Create a hex decoding module
+   */
+  HexDecode();
+
+private:
+  /**
+   * @brief Decode data @p buf, and write the result into output buffer directly.
+   *
+   * @return number of input bytes that are accepted
+   */
+  virtual size_t
+  convert(const uint8_t* buf, size_t size) final;
+
+  /**
+   * @throws Error if pending byte exists.
+   */
+  virtual void
+  finalize() final;
+
+  /**
+   * @return results of decoding concatenation of @p oddByte and @p hex.
+   */
+  unique_ptr<Transform::OBuffer>
+  toBytes(const uint8_t* hex, size_t hexLen);
+
+private:
+  bool m_hasOddByte;
+  uint8_t m_oddByte;
+};
+
+unique_ptr<Transform>
+hexDecode();
+
+} // namespace transform
+} // namespace security
+} // namespace ndn
+
+#endif // NDN_CXX_SECURITY_TRANSFORM_HEX_DECODE_HPP