diff --git a/core/logger.hpp b/core/logger.hpp
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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014,  Regents of the University of California
+ *
+ * This file is part of NSL (NDN Signature Logger).
+ * See AUTHORS.md for complete list of NSL authors and contributors.
+ *
+ * NSL is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NSL 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NSL, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of nsl authors and contributors.
+ */
+
+#ifndef NSL_CORE_LOGGER_HPP
+#define NSL_CORE_LOGGER_HPP
+
+#include "common.hpp"
+#include "logger-response.hpp"
+#include "db.hpp"
+#include "policy-checker.hpp"
+#include "merkle-tree.hpp"
+#include "util/non-negative-integer.hpp"
+#include <ndn-cxx/face.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/security/validator-config.hpp>
+
+namespace nsl {
+
+class Logger
+{
+public:
+  class Error : public std::runtime_error
+  {
+  public:
+    explicit
+    Error(const std::string& what)
+      : std::runtime_error(what)
+    {
+    }
+  };
+
+public:
+  Logger(ndn::Face& face, const std::string& configFile);
+
+  NonNegativeInteger
+  addSelfSignedCert(ndn::IdentityCertificate& cert, const Timestamp& timestamp);
+
+NSL_PUBLIC_WITH_TESTS_ELSE_PRIVATE:
+  void
+  initializeKeys();
+
+  void
+  loadConfiguration(const std::string& filename);
+
+  void
+  onSubTreeInterest(const ndn::InterestFilter& interestFilter, const Interest& interest);
+
+  void
+  onLeafInterest(const ndn::InterestFilter& interestFilter, const Interest& interest);
+
+  void
+  onLogRequestInterest(const ndn::InterestFilter& interestFilter, const Interest& interest);
+
+  void
+  requestValidatedCallback(const shared_ptr<const Interest>& interest);
+
+  void
+  dataReceivedCallback(const Interest& interest, Data& data,
+                       const NonNegativeInteger& signerSeqNo,
+                       const Interest& reqInterest);
+
+  void
+  dataTimeoutCallback(const Interest& interest, int nRetrials,
+                      const NonNegativeInteger& signerSeqNo,
+                      const Interest& reqInterest);
+
+  void
+  makeLogResponse(const Interest& reqInterest, const LoggerResponse& response);
+
+  const Name&
+  getLoggerName() const
+  {
+    return m_loggerName;
+  }
+
+  const Name&
+  getTreePrefix() const
+  {
+    return m_treePrefix;
+  }
+
+  const Name&
+  getLeafPrefix() const
+  {
+    return m_leafPrefix;
+  }
+
+  const Name&
+  getLogPrefix() const
+  {
+    return m_logPrefix;
+  }
+
+  Db&
+  getDb()
+  {
+    return m_db;
+  }
+
+private:
+  static const int N_DATA_FETCHING_RETRIAL;
+
+private:
+  ndn::Face& m_face;
+  Name m_loggerName;
+  Name m_treePrefix;
+  Name m_leafPrefix;
+  Name m_logPrefix;
+
+  Db m_db;
+  MerkleTree  m_merkleTree;
+
+  ndn::KeyChain m_keyChain;
+  shared_ptr<ndn::IdentityCertificate> m_dskCert;
+
+  ndn::ValidatorConfig m_validator;
+  PolicyChecker m_policyChecker;
+};
+
+} // namespace nsl
+
+#endif // NSL_CORE_LOGGER_HPP