diff --git a/src/security/pib/detail/key-impl.cpp b/src/security/pib/detail/key-impl.cpp
new file mode 100644
index 0000000..35a0de6
--- /dev/null
+++ b/src/security/pib/detail/key-impl.cpp
@@ -0,0 +1,149 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 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 "key-impl.hpp"
+#include "../pib-impl.hpp"
+#include "../pib.hpp"
+#include "../../transform/public-key.hpp"
+
+namespace ndn {
+namespace security {
+namespace pib {
+namespace detail {
+
+KeyImpl::KeyImpl(const Name& keyName, const uint8_t* key, size_t keyLen, shared_ptr<PibImpl> impl)
+  : m_identity(v2::extractIdentityFromKeyName(keyName))
+  , m_keyName(keyName)
+  , m_key(key, keyLen)
+  , m_isDefaultCertificateLoaded(false)
+  , m_certificates(keyName, impl)
+  , m_impl(impl)
+{
+  BOOST_ASSERT(impl != nullptr);
+
+  if (m_impl->hasKey(m_keyName)) {
+    BOOST_THROW_EXCEPTION(Pib::Error("Cannot overwrite existing key " + m_keyName.toUri()));
+  }
+
+  transform::PublicKey publicKey;
+  try {
+    publicKey.loadPkcs8(key, keyLen);
+  }
+  catch (transform::PublicKey::Error&) {
+    BOOST_THROW_EXCEPTION(std::invalid_argument("Invalid key bits"));
+  }
+  m_keyType = publicKey.getKeyType();
+
+  m_impl->addKey(m_identity, m_keyName, key, keyLen);
+}
+
+KeyImpl::KeyImpl(const Name& keyName, shared_ptr<PibImpl> impl)
+  : m_identity(v2::extractIdentityFromKeyName(keyName))
+  , m_keyName(keyName)
+  , m_isDefaultCertificateLoaded(false)
+  , m_certificates(keyName, impl)
+  , m_impl(impl)
+{
+  BOOST_ASSERT(impl != nullptr);
+
+  m_key = m_impl->getKeyBits(m_keyName);
+
+  transform::PublicKey key;
+  key.loadPkcs8(m_key.buf(), m_key.size());
+  m_keyType = key.getKeyType();
+}
+
+void
+KeyImpl::addCertificate(const v2::Certificate& certificate)
+{
+  BOOST_ASSERT(m_certificates.isConsistent());
+
+  if (m_certificates.find(certificate.getName()) != m_certificates.end()) {
+    BOOST_THROW_EXCEPTION(Pib::Error("Cannot overwrite existing certificate " + certificate.getName().toUri()));
+  }
+
+  m_certificates.add(certificate);
+}
+
+void
+KeyImpl::removeCertificate(const Name& certName)
+{
+  BOOST_ASSERT(m_certificates.isConsistent());
+
+  if (m_isDefaultCertificateLoaded && m_defaultCertificate.getName() == certName)
+    m_isDefaultCertificateLoaded = false;
+
+  m_certificates.remove(certName);
+}
+
+v2::Certificate
+KeyImpl::getCertificate(const Name& certName) const
+{
+  BOOST_ASSERT(m_certificates.isConsistent());
+
+  return m_certificates.get(certName);
+}
+
+const CertificateContainer&
+KeyImpl::getCertificates() const
+{
+  BOOST_ASSERT(m_certificates.isConsistent());
+
+  return m_certificates;
+}
+
+const v2::Certificate&
+KeyImpl::setDefaultCertificate(const Name& certName)
+{
+  BOOST_ASSERT(m_certificates.isConsistent());
+
+  m_defaultCertificate = m_certificates.get(certName);
+  m_impl->setDefaultCertificateOfKey(m_keyName, certName);
+  m_isDefaultCertificateLoaded = true;
+  return m_defaultCertificate;
+}
+
+const v2::Certificate&
+KeyImpl::setDefaultCertificate(const v2::Certificate& certificate)
+{
+  addCertificate(certificate);
+  return setDefaultCertificate(certificate.getName());
+}
+
+const v2::Certificate&
+KeyImpl::getDefaultCertificate() const
+{
+  BOOST_ASSERT(m_certificates.isConsistent());
+
+  if (!m_isDefaultCertificateLoaded) {
+    m_defaultCertificate = m_impl->getDefaultCertificateOfKey(m_keyName);
+    m_isDefaultCertificateLoaded = true;
+  }
+
+  BOOST_ASSERT(m_impl->getDefaultCertificateOfKey(m_keyName).wireEncode() == m_defaultCertificate.wireEncode());
+
+  return m_defaultCertificate;
+}
+
+} // namespace detail
+} // namespace pib
+} // namespace security
+} // namespace ndn