diff --git a/tools/pib/key-cache.cpp b/tools/pib/key-cache.cpp
new file mode 100644
index 0000000..431e635
--- /dev/null
+++ b/tools/pib/key-cache.cpp
@@ -0,0 +1,106 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014 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-cache.hpp"
+
+namespace ndn {
+namespace pib {
+
+KeyCacheEntry::KeyCacheEntry(const Name& name, shared_ptr<PublicKey> key)
+  : name(name)
+  , key(key)
+{
+  BOOST_ASSERT(static_cast<bool>(key));
+}
+
+KeyCache::KeyCache(size_t capacity)
+  : m_capacity(capacity)
+{
+}
+
+void
+KeyCache::insert(const Name& name, shared_ptr<PublicKey> key)
+{
+  // check if key exist
+  KeyContainer::index<byName>::type::iterator it = m_keys.get<byName>().find(name);
+  if (it != m_keys.get<byName>().end()) {
+    adjustLru(it);
+    return;
+  }
+
+  // evict key when capacity is reached
+  if (size() >= m_capacity)
+    evictKey();
+
+  // insert entry
+  m_keys.insert(KeyCacheEntry(name, key));
+}
+
+shared_ptr<PublicKey>
+KeyCache::find(const Name& name) const
+{
+  // check if key exist
+  KeyContainer::index<byName>::type::iterator it = m_keys.get<byName>().find(name);
+  if (it == m_keys.get<byName>().end())
+    return shared_ptr<PublicKey>();
+  else {
+    // adjust lru
+    shared_ptr<PublicKey> key = it->key;
+    adjustLru(it);
+    return key;
+  }
+}
+
+void
+KeyCache::erase(const Name& name)
+{
+  // check if key exist
+  KeyContainer::index<byName>::type::iterator it = m_keys.get<byName>().find(name);
+  if (it != m_keys.get<byName>().end()) {
+    m_keys.erase(it);
+  }
+}
+
+size_t
+KeyCache::size() const
+{
+  return m_keys.size();
+}
+
+void
+KeyCache::evictKey()
+{
+  if (!m_keys.get<byUsedTime>().empty()) {
+    KeyContainer::index<byUsedTime>::type::iterator it = m_keys.get<byUsedTime>().begin();
+    m_keys.erase(m_keys.project<0>(it));
+  }
+}
+
+void
+KeyCache::adjustLru(KeyContainer::iterator it) const
+{
+  KeyCacheEntry entry = std::move(*it);
+  m_keys.erase(it);
+  m_keys.insert(entry);
+}
+
+} // namespace pib
+} // namespace ndn