diff --git a/crypto_des_cbc.h b/crypto_des_cbc.h
new file mode 100644
index 0000000..3a3d84f
--- /dev/null
+++ b/crypto_des_cbc.h
@@ -0,0 +1,55 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SHILL_CRYPTO_DES_CBC_
+#define SHILL_CRYPTO_DES_CBC_
+
+#include <vector>
+
+#include <gtest/gtest_prod.h>  // for FRIEND_TEST
+
+#include "shill/crypto_interface.h"
+
+class FilePath;
+
+namespace shill {
+
+class GLib;
+
+// DES-CBC crypto module implementation.
+class CryptoDESCBC : public CryptoInterface {
+ public:
+  static const char kID[];
+
+  CryptoDESCBC(GLib *glib);
+
+  // Sets the DES key to the last |kBlockSize| bytes of |key_matter_path| and
+  // the DES initialization vector to the second to last |kBlockSize| bytes of
+  // |key_matter_path|. Returns true on success.
+  bool LoadKeyMatter(const FilePath &path);
+
+  // Inherited from CryptoInterface.
+  virtual std::string GetID();
+  virtual bool Encrypt(const std::string &plaintext, std::string *ciphertext);
+  virtual bool Decrypt(const std::string &ciphertext, std::string *plaintext);
+
+  const std::vector<char> &key() const { return key_; }
+  const std::vector<char> &iv() const { return iv_; }
+
+ private:
+  FRIEND_TEST(CryptoDESCBCTest, Decrypt);
+  FRIEND_TEST(CryptoDESCBCTest, Encrypt);
+
+  static const int kBlockSize;
+  static const char kSentinel[];
+  static const char kVersion2Prefix[];
+
+  GLib *glib_;
+  std::vector<char> key_;
+  std::vector<char> iv_;
+};
+
+}  // namespace shill
+
+#endif  // SHILL_CRYPTO_DES_CBC_