diff --git a/src/security/tpm/back-end-file.cpp b/src/security/tpm/back-end-file.cpp
new file mode 100644
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--- /dev/null
+++ b/src/security/tpm/back-end-file.cpp
@@ -0,0 +1,192 @@
+/* -*- 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 "back-end-file.hpp"
+#include "key-handle-mem.hpp"
+#include "../transform.hpp"
+#include "../transform/private-key.hpp"
+#include "../../encoding/buffer-stream.hpp"
+#include <unordered_map>
+#include <fstream>
+#include <cstdlib>
+#include <boost/filesystem.hpp>
+
+namespace ndn {
+namespace security {
+namespace tpm {
+
+using transform::PrivateKey;
+
+class BackEndFile::Impl
+{
+public:
+  explicit
+  Impl(const std::string& dir)
+  {
+    if (!dir.empty()) {
+      keystorePath = boost::filesystem::path(dir);
+    }
+#ifdef NDN_CXX_HAVE_TESTS
+    else if (getenv("TEST_HOME") != nullptr) {
+      keystorePath = boost::filesystem::path(getenv("TEST_HOME")) / ".ndn";
+    }
+#endif // NDN_CXX_HAVE_TESTS
+    else if (getenv("HOME") != nullptr) {
+      keystorePath = boost::filesystem::path(getenv("HOME")) / ".ndn";
+    }
+    else {
+      keystorePath = boost::filesystem::current_path() / ".ndn";
+    }
+
+    keystorePath /= "ndnsec-key-file";
+    boost::filesystem::create_directories(keystorePath);
+  }
+
+  boost::filesystem::path
+  toFileName(const Name& keyName)
+  {
+    std::stringstream os;
+    {
+      using namespace transform;
+      bufferSource(keyName.wireEncode().wire(), keyName.wireEncode().size()) >>
+        digestFilter(DigestAlgorithm::SHA256) >> hexEncode() >> streamSink(os);
+    }
+    return keystorePath / (os.str() + ".privkey");
+  }
+
+public:
+  boost::filesystem::path keystorePath;
+};
+
+BackEndFile::BackEndFile(const std::string& location)
+  : m_impl(new Impl(location))
+{
+}
+
+BackEndFile::~BackEndFile() = default;
+
+bool
+BackEndFile::doHasKey(const Name& keyName) const
+{
+  if (!boost::filesystem::exists(m_impl->toFileName(keyName)))
+    return false;
+
+  try {
+    loadKey(keyName);
+    return true;
+  }
+  catch (const std::runtime_error&) {
+    return false;
+  }
+}
+
+unique_ptr<KeyHandle>
+BackEndFile::doGetKeyHandle(const Name& keyName) const
+{
+  if (!doHasKey(keyName))
+    return nullptr;
+
+  return make_unique<KeyHandleMem>(loadKey(keyName));
+}
+
+unique_ptr<KeyHandle>
+BackEndFile::doCreateKey(const Name& identityName, const KeyParams& params)
+{
+  shared_ptr<PrivateKey> key(transform::generatePrivateKey(params).release());
+  unique_ptr<KeyHandle> keyHandle = make_unique<KeyHandleMem>(key);
+
+  setKeyName(*keyHandle, identityName, params);
+
+  try {
+    saveKey(keyHandle->getKeyName(), key);
+    return keyHandle;
+  }
+  catch (const std::runtime_error& e) {
+    BOOST_THROW_EXCEPTION(Error(std::string("Cannot write key to disk: ") + e.what()));
+  }
+}
+
+void
+BackEndFile::doDeleteKey(const Name& keyName)
+{
+  boost::filesystem::path keyPath(m_impl->toFileName(keyName));
+
+  if (boost::filesystem::exists(keyPath)) {
+    try {
+      boost::filesystem::remove(keyPath);
+    }
+    catch (const boost::filesystem::filesystem_error&) {
+      BOOST_THROW_EXCEPTION(Error("Cannot delete key"));
+    }
+  }
+}
+
+ConstBufferPtr
+BackEndFile::doExportKey(const Name& keyName, const char* pw, size_t pwLen)
+{
+  shared_ptr<PrivateKey> key;
+  try {
+    key = loadKey(keyName);
+  }
+  catch (const PrivateKey::Error&) {
+    BOOST_THROW_EXCEPTION(Error("Cannot export private key"));
+  }
+  OBufferStream os;
+  key->savePkcs8(os, pw, pwLen);
+  return os.buf();
+}
+
+void
+BackEndFile::doImportKey(const Name& keyName, const uint8_t* buf, size_t size, const char* pw, size_t pwLen)
+{
+  try {
+    auto key = make_shared<PrivateKey>();
+    key->loadPkcs8(buf, size, pw, pwLen);
+    saveKey(keyName, key);
+  }
+  catch (const PrivateKey::Error&) {
+    BOOST_THROW_EXCEPTION(Error("Cannot import private key"));
+  }
+}
+
+shared_ptr<PrivateKey>
+BackEndFile::loadKey(const Name& keyName) const
+{
+  auto key = make_shared<PrivateKey>();
+  std::fstream is(m_impl->toFileName(keyName).string(), std::ios_base::in);
+  key->loadPkcs1Base64(is);
+  return key;
+}
+
+void
+BackEndFile::saveKey(const Name& keyName, shared_ptr<PrivateKey> key)
+{
+  std::string fileName = m_impl->toFileName(keyName).string();
+  std::fstream os(fileName, std::ios_base::out);
+  key->savePkcs1Base64(os);
+
+  // set file permission
+  chmod(fileName.c_str(), 0000400);
+}
+
+} // namespace tpm
+} // namespace security
+} // namespace ndn