diff --git a/tools/pib/default-query-processor.cpp b/tools/pib/default-query-processor.cpp
new file mode 100644
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--- /dev/null
+++ b/tools/pib/default-query-processor.cpp
@@ -0,0 +1,199 @@
+/* -*- 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 "default-query-processor.hpp"
+#include "encoding/pib-encoding.hpp"
+
+#include <boost/lexical_cast.hpp>
+
+namespace ndn {
+namespace pib {
+
+using std::string;
+
+const size_t DefaultQueryProcessor::DEFAULT_QUERY_LENGTH = 5;
+
+DefaultQueryProcessor::DefaultQueryProcessor(PibDb& db)
+  : m_db(db)
+{
+}
+
+std::pair<bool, Block>
+DefaultQueryProcessor::operator()(const Interest& interest)
+{
+  const Name& interestName = interest.getName();
+
+  // handle pib query: /localhost/pib/[UserName]/default/param
+  if (interestName.size() != DEFAULT_QUERY_LENGTH) {
+    // malformed interest, discard
+    return std::make_pair(false, Block());
+  }
+
+  DefaultParam param;
+
+  try {
+    param.wireDecode(interestName.get(OFFSET_PARAM).blockFromValue());
+  }
+  catch (const tlv::Error& e) {
+    PibError error(ERR_WRONG_PARAM, "error in parsing param: " + string(e.what()));
+    return std::make_pair(true, error.wireEncode());
+  }
+
+  switch (param.getTargetType()) {
+  case TYPE_ID:
+    return processDefaultIdQuery(param);
+  case TYPE_KEY:
+    return processDefaultKeyQuery(param);
+  case TYPE_CERT:
+    return processDefaultCertQuery(param);
+  default:
+    {
+      PibError error(ERR_WRONG_PARAM,
+                     "target type is not supported: " +
+                     boost::lexical_cast<string>(param.getTargetType()));
+      return std::make_pair(true, error.wireEncode());
+    }
+  }
+}
+
+std::pair<bool, Block>
+DefaultQueryProcessor::processDefaultIdQuery(const DefaultParam& param)
+{
+  if (param.getOriginType() == TYPE_USER) {
+    try {
+      PibIdentity result(m_db.getDefaultIdentity());
+      return std::make_pair(true, result.wireEncode());
+    }
+    catch (PibDb::Error&) {
+      PibError error(ERR_NO_DEFAULT_ID, "default identity does not exist");
+      return std::make_pair(true, error.wireEncode());
+    }
+  }
+  else {
+    PibError error(ERR_WRONG_PARAM,
+                   "origin type of id target must be USER(0), but gets: " +
+                   boost::lexical_cast<string>(param.getOriginType()));
+    return std::make_pair(true, error.wireEncode());
+  }
+}
+
+std::pair<bool, Block>
+DefaultQueryProcessor::processDefaultKeyQuery(const DefaultParam& param)
+{
+  Name identity;
+  if (param.getOriginType() == TYPE_ID)
+    identity = param.getOriginName();
+  else if (param.getOriginType() == TYPE_USER) {
+    try {
+      identity = m_db.getDefaultIdentity();
+    }
+    catch (PibDb::Error&) {
+      PibError error(ERR_NO_DEFAULT_ID, "default identity does not exist");
+      return std::make_pair(true, error.wireEncode());
+    }
+  }
+  else {
+    PibError error(ERR_WRONG_PARAM,
+                   "origin type of key target must be ID(1) or USER(0), but gets: " +
+                   boost::lexical_cast<string>(param.getOriginType()));
+    return std::make_pair(true, error.wireEncode());
+  }
+
+  try {
+    Name keyName = m_db.getDefaultKeyNameOfIdentity(identity);
+    shared_ptr<PublicKey> key = m_db.getKey(keyName);
+
+    if (key == nullptr) {
+      PibError error(ERR_NO_DEFAULT_KEY, "default key does not exist");
+      return std::make_pair(true, error.wireEncode());
+    }
+
+    PibPublicKey result(keyName, *key);
+    return std::make_pair(true, result.wireEncode());
+  }
+  catch (PibDb::Error& e) {
+    PibError error(ERR_NO_DEFAULT_KEY,
+                   "default key does not exist: " + string(e.what()));
+    return std::make_pair(true, error.wireEncode());
+  }
+}
+
+std::pair<bool, Block>
+DefaultQueryProcessor::processDefaultCertQuery(const DefaultParam& param)
+{
+  Name identity;
+  if (param.getOriginType() == TYPE_USER) {
+    try {
+      identity = m_db.getDefaultIdentity();
+    }
+    catch (PibDb::Error&) {
+      PibError error(ERR_NO_DEFAULT_ID, "default identity does not exist");
+      return std::make_pair(true, error.wireEncode());
+    }
+  }
+  else if (param.getOriginType() == TYPE_ID)
+    identity = param.getOriginName();
+  else if (param.getOriginType() != TYPE_KEY) {
+    PibError error(ERR_WRONG_PARAM,
+                   "origin type of cert target must be KEY(2), ID(1) or USER(0), but gets: " +
+                   boost::lexical_cast<string>(param.getOriginType()));
+    return std::make_pair(true, error.wireEncode());
+  }
+
+  Name keyName;
+  if (param.getOriginType() == TYPE_KEY) {
+    keyName = param.getOriginName();
+    if (keyName.size() < 1) {
+      PibError error(ERR_WRONG_PARAM,
+                     "key name must contain key id component");
+      return std::make_pair(true, error.wireEncode());
+    }
+  }
+  else {
+    try {
+      keyName = m_db.getDefaultKeyNameOfIdentity(identity);
+    }
+    catch (PibDb::Error&) {
+      PibError error(ERR_NO_DEFAULT_KEY, "default key does not exist");
+      return std::make_pair(true, error.wireEncode());
+    }
+  }
+
+  try {
+    Name certName = m_db.getDefaultCertNameOfKey(keyName);
+    shared_ptr<IdentityCertificate> certificate = m_db.getCertificate(certName);
+
+    if (certificate == nullptr) {
+      PibError error (ERR_NO_DEFAULT_CERT, "default cert does not exist");
+      return std::make_pair(true, error.wireEncode());
+    }
+
+    PibCertificate result(*certificate);
+    return std::make_pair(true, result.wireEncode());
+  }
+  catch (PibDb::Error&) {
+    PibError error(ERR_NO_DEFAULT_CERT, "default cert does not exist");
+    return std::make_pair(true, error.wireEncode());
+  }
+}
+
+} // namespace pib
+} // namespace ndn