diff --git a/src/security/pib-memory.cpp b/src/security/pib-memory.cpp
new file mode 100644
index 0000000..397b0db
--- /dev/null
+++ b/src/security/pib-memory.cpp
@@ -0,0 +1,257 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2015 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 "pib-memory.hpp"
+#include "pib.hpp"
+
+namespace ndn {
+namespace security {
+
+PibMemory::PibMemory()
+  : m_hasDefaultIdentity(false)
+{
+}
+
+void
+PibMemory::setTpmLocator(const std::string& tpmLocator)
+{
+  throw Error("PibMemory does not need a locator");
+}
+
+std::string
+PibMemory::getTpmLocator() const
+{
+  return "tpm-memory:";
+}
+
+bool
+PibMemory::hasIdentity(const Name& identity) const
+{
+  return (m_identities.count(identity) > 0);
+}
+
+void
+PibMemory::addIdentity(const Name& identity)
+{
+  m_identities.insert(identity);
+
+  if (!m_hasDefaultIdentity) {
+    m_defaultIdentity = identity;
+    m_hasDefaultIdentity = true;
+  }
+}
+
+void
+PibMemory::removeIdentity(const Name& identity)
+{
+  m_identities.erase(identity);
+  if (identity == m_defaultIdentity)
+    m_hasDefaultIdentity = false;
+
+  auto keyIds = this->getKeysOfIdentity(identity);
+  for (const name::Component& keyId : keyIds) {
+    this->removeKey(identity, keyId);
+  }
+}
+
+std::set<Name>
+PibMemory::getIdentities() const
+{
+  return m_identities;
+}
+
+void
+PibMemory::setDefaultIdentity(const Name& identityName)
+{
+  addIdentity(identityName);
+  m_defaultIdentity = identityName;
+  m_hasDefaultIdentity = true;
+}
+
+Name
+PibMemory::getDefaultIdentity() const
+{
+  if (m_hasDefaultIdentity)
+    return m_defaultIdentity;
+
+  throw Pib::Error("No default identity");
+}
+
+bool
+PibMemory::hasKey(const Name& identity, const name::Component& keyId) const
+{
+  return (m_keys.count(getKeyName(identity, keyId)) > 0);
+}
+
+void
+PibMemory::addKey(const Name& identity, const name::Component& keyId, const PublicKey& publicKey)
+{
+  this->addIdentity(identity);
+
+  Name keyName = getKeyName(identity, keyId);
+  m_keys[keyName] = publicKey;
+
+  if (m_defaultKey.find(identity) == m_defaultKey.end())
+    m_defaultKey[identity] = keyName;
+}
+
+void
+PibMemory::removeKey(const Name& identity, const name::Component& keyId)
+{
+  Name keyName = getKeyName(identity, keyId);
+  m_keys.erase(keyName);
+  m_defaultKey.erase(identity);
+
+
+  auto certNames = this->getCertificatesOfKey(identity, keyId);
+  for (const auto& certName : certNames) {
+    this->removeCertificate(certName);
+  }
+}
+
+PublicKey
+PibMemory::getKeyBits(const Name& identity, const name::Component& keyId) const
+{
+  if (!hasKey(identity, keyId))
+    throw Pib::Error("No key");
+
+  auto it = m_keys.find(getKeyName(identity, keyId));
+  return it->second;
+}
+
+std::set<name::Component>
+PibMemory::getKeysOfIdentity(const Name& identity) const
+{
+  std::set<name::Component> ids;
+  for (const auto& it : m_keys) {
+    if (identity == it.first.getPrefix(-1))
+      ids.insert(it.first.get(-1));
+  }
+  return ids;
+}
+
+void
+PibMemory::setDefaultKeyOfIdentity(const Name& identity, const name::Component& keyId)
+{
+  Name keyName = getKeyName(identity, keyId);
+
+  if (!hasKey(identity, keyId))
+    throw Pib::Error("No key");
+
+  m_defaultKey[identity] = keyName;
+}
+
+name::Component
+PibMemory::getDefaultKeyOfIdentity(const Name& identity) const
+{
+  auto it = m_defaultKey.find(identity);
+  if (it == m_defaultKey.end())
+    throw Pib::Error("No default key");
+
+  return it->second.get(-1);
+}
+
+Name
+PibMemory::getKeyName(const Name& identity, const name::Component& keyId) const
+{
+  Name keyName = identity;
+  keyName.append(keyId);
+  return keyName;
+}
+
+bool
+PibMemory::hasCertificate(const Name& certName) const
+{
+  return (m_certs.count(certName) > 0);
+}
+
+void
+PibMemory::addCertificate(const IdentityCertificate& certificate)
+{
+  this->addKey(certificate.getPublicKeyName().getPrefix(-1),
+               certificate.getPublicKeyName().get(-1),
+               certificate.getPublicKeyInfo());
+
+  m_certs[certificate.getName()] = certificate;
+
+  const Name& keyName = certificate.getPublicKeyName();
+  if (m_defaultCert.find(keyName) == m_defaultCert.end())
+    m_defaultCert[keyName] = certificate.getName();
+}
+
+void
+PibMemory::removeCertificate(const Name& certName)
+{
+  m_certs.erase(certName);
+  m_defaultCert.erase(IdentityCertificate::certificateNameToPublicKeyName(certName));
+}
+
+IdentityCertificate
+PibMemory::getCertificate(const Name& certName) const
+{
+  if (!hasCertificate(certName))
+    throw Pib::Error("No cert");
+
+  auto it = m_certs.find(certName);
+  return it->second;
+}
+
+std::set<Name>
+PibMemory::getCertificatesOfKey(const Name& identity, const name::Component& keyId) const
+{
+  Name keyName = getKeyName(identity, keyId);
+
+  std::set<Name> certNames;
+  for (const auto& it : m_certs) {
+    if (it.second.getPublicKeyName() == keyName)
+      certNames.insert(it.first);
+  }
+  return certNames;
+}
+
+void
+PibMemory::setDefaultCertificateOfKey(const Name& identity, const name::Component& keyId, const Name& certName)
+{
+  if (!hasCertificate(certName))
+    throw Pib::Error("No cert");
+
+  Name keyName = getKeyName(identity, keyId);
+  m_defaultCert[keyName] = certName;
+}
+
+IdentityCertificate
+PibMemory::getDefaultCertificateOfKey(const Name& identity, const name::Component& keyId) const
+{
+  Name keyName = getKeyName(identity, keyId);
+
+  auto it = m_defaultCert.find(keyName);
+  if (it == m_defaultCert.end())
+    throw Pib::Error("No default certificate");
+
+  auto certIt = m_certs.find(it->second);
+  if (certIt == m_certs.end())
+    throw Pib::Error("No default certificate");
+  else
+    return certIt->second;
+}
+
+} // namespace security
+} // namespace ndn