diff --git a/core/merkle-tree-sqlite3.cpp b/core/merkle-tree-sqlite3.cpp
new file mode 100644
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--- /dev/null
+++ b/core/merkle-tree-sqlite3.cpp
@@ -0,0 +1,332 @@
+/* -*- 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/>.
+ *
+ * @author Peizhen Guo <patrick.guopz@gmail.com>
+ */
+
+#include "merkle-tree-sqlite3.hpp"
+#include <stdlib.h>
+#include <boost/filesystem.hpp>
+
+
+namespace nsl {
+
+static const std::string INIT_SUBTREE_TABLE = "\
+CREATE TABLE IF NOT EXISTS                                           \n \
+  SubTree(                                                           \n \
+      subTree_sequence     INTEGER,                                  \n \
+      subTree_level        INTEGER,                                  \n \
+      subTree_info         BLOB,                                     \n \
+                                                                     \
+      PRIMARY KEY (subTree_sequence, subTree_level)                  \n \
+  );                                                                 \n \
+                                                                     \
+CREATE INDEX subTree_index ON SubTree(subTree_sequence);             \n \
+";
+
+static const std::string INIT_LEAF_TABLE = "\
+CREATE TABLE IF NOT EXISTS                                           \n \
+  Leaf(                                                              \n \
+      leaf_sequence     INTEGER,                                     \n \
+      leaf_info         BLOB,                                        \n \
+                                                                     \
+      PRIMARY KEY (leaf_sequence)                                    \n \
+  );                                                                 \n \
+                                                                     \
+CREATE INDEX leaf_index ON Leaf(leaf_sequence);                      \n \
+";
+
+/**
+ * A utility function to call the normal sqlite3_bind_text where the value and length are
+ * value.c_str() and value.size().
+ */
+static int sqlite3_bind_text(sqlite3_stmt* statement,
+                             int index,
+                             const std::string& value,
+                             void(*destructor)(void*))
+{
+  return sqlite3_bind_text(statement, index, value.c_str(), value.size(), destructor);
+}
+
+
+MerkleTreeSqlite3::MerkleTreeSqlite3()
+{
+  boost::filesystem::path identityDir = boost::filesystem::path("/Users/GPZ/Develop/nslDB");
+  boost::filesystem::create_directories(identityDir);
+
+  /// @todo Add define for windows/unix in wscript. The following may completely fail on windows
+  int res = sqlite3_open_v2((identityDir / "nsl-merkle-tree.db").c_str(), &m_database,
+                            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
+#ifdef NDN_CXX_DISABLE_SQLITE3_FS_LOCKING
+                            "unix-dotfile"
+#else
+                            0
+#endif
+                            );
+
+  if (res != SQLITE_OK)
+    std::cout << "DB cannot be opened/created";
+
+  //Check if SubTree table exists;
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT name FROM sqlite_master WHERE type='table' And name='SubTree'",
+                     -1, &statement, 0);
+  res = sqlite3_step(statement);
+
+  bool SubTreeTableExists = false;
+  if (res == SQLITE_ROW)
+    SubTreeTableExists = true;
+
+  sqlite3_finalize(statement);
+
+  if (!SubTreeTableExists)
+    {
+      char* errorMessage = 0;
+      res = sqlite3_exec(m_database, INIT_SUBTREE_TABLE.c_str(), NULL, NULL, &errorMessage);
+
+      if (res != SQLITE_OK && errorMessage != 0)
+        {
+          sqlite3_free(errorMessage);
+        }
+    }
+
+  //Check if Leaf table exists;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT name FROM sqlite_master WHERE type='table' And name='Leaf'",
+                     -1, &statement, 0);
+  res = sqlite3_step(statement);
+
+  bool LeafTableExists = false;
+  if (res == SQLITE_ROW)
+    LeafTableExists = true;
+
+  sqlite3_finalize(statement);
+
+  if (!LeafTableExists)
+    {
+      char* errorMessage = 0;
+      res = sqlite3_exec(m_database, INIT_LEAF_TABLE.c_str(), NULL, NULL, &errorMessage);
+
+      if (res != SQLITE_OK && errorMessage != 0)
+        {
+          sqlite3_free(errorMessage);
+        }
+    }
+
+}
+
+
+MerkleTreeSqlite3::~MerkleTreeSqlite3()
+{
+}
+
+
+void
+MerkleTreeSqlite3::addSubTree(SubTreePtr oldSubTree)
+{
+  Index old_idx = oldSubTree->getRootIndex();
+  std::string old_info = oldSubTree->encoding();
+
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "INSERT OR REPLACE INTO SubTree \
+                      (subTree_sequence, subTree_level, subTree_info)   \
+                      values (?, ?, ?)",
+                     -1, &statement, 0);
+  sqlite3_bind_int64(statement, 1, old_idx.number);
+  sqlite3_bind_int64(statement, 2, old_idx.level);
+  sqlite3_bind_text(statement, 3, old_info, SQLITE_TRANSIENT);
+  sqlite3_step(statement);
+  sqlite3_finalize(statement);
+}
+
+
+std::string
+MerkleTreeSqlite3::getSubTree(Index rootIndex)
+{
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT subTree_info FROM SubTree \
+                      WHERE subTree_sequence=? AND subTree_level=?",
+                     -1, &statement, 0);
+  sqlite3_bind_int64(statement, 1, rootIndex.number);
+  sqlite3_bind_int64(statement, 2, rootIndex.level);
+  int res = sqlite3_step(statement);
+  std::string result;
+  if (res == SQLITE_ROW)
+    {
+      result = std::string(reinterpret_cast<const char *>(sqlite3_column_text(statement, 0)),
+                           sqlite3_column_bytes(statement, 0));
+      sqlite3_finalize(statement);
+      return result;
+    }
+  else
+    {
+      sqlite3_finalize(statement);
+      return result;
+    }
+}
+
+
+bool
+MerkleTreeSqlite3::doesSubTreeExist(Index rootIndex)
+{
+  bool result = false;
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT count(*) FROM SubTree WHERE subTree_sequence=? AND subTree_level=?",
+                     -1, &statement, 0);
+  sqlite3_bind_int64(statement, 1, rootIndex.number);
+  sqlite3_bind_int64(statement, 2, rootIndex.level);
+  int res = sqlite3_step(statement);
+  if (res == SQLITE_ROW)
+    {
+      int countAll = sqlite3_column_int(statement, 0);
+      if (countAll > 0)
+        result = true;
+    }
+  sqlite3_finalize(statement);
+  return result;
+}
+
+
+void
+MerkleTreeSqlite3::deleteSubTree(Index rootIndex)
+{
+  sqlite3_stmt* stmt;
+  sqlite3_prepare_v2(m_database, "DELETE FROM SubTree WHERE subTree_sequence=? AND subTree_level=?",
+                     -1, &stmt, 0);
+  sqlite3_bind_int64(stmt, 1, rootIndex.number);
+  sqlite3_bind_int64(stmt, 2, rootIndex.level);
+  sqlite3_step(stmt);
+  sqlite3_finalize(stmt);
+}
+
+
+void
+MerkleTreeSqlite3::getAllSubTree(std::vector<std::string> subTreeInfoList)
+{
+  sqlite3_stmt* stmt;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT subTree_info FROM SubTree",
+                     -1, &stmt, 0);
+  while (sqlite3_step(stmt) == SQLITE_ROW)
+    subTreeInfoList.push_back(std::string(reinterpret_cast<const char *>
+                                          (sqlite3_column_text(stmt, 0)),
+                                          sqlite3_column_bytes(stmt, 0)));
+
+  sqlite3_finalize(stmt);
+}
+
+
+// For leafInfo
+
+void
+MerkleTreeSqlite3::addLeafInfo(uint64_t sequence, ndn::ConstBufferPtr buf_ptr)
+{
+
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "INSERT OR REPLACE INTO Leaf  \
+                      (leaf_sequence, leaf_info)   \
+                      values (?, ?)", -1, &statement, 0);
+  sqlite3_bind_int64(statement, 1, sequence);
+  sqlite3_bind_blob(statement, 2, buf_ptr->buf(), buf_ptr->size(), SQLITE_STATIC);
+  sqlite3_step(statement);
+  sqlite3_finalize(statement);
+}
+
+
+ndn::ConstBufferPtr
+MerkleTreeSqlite3::getLeafInfo(uint64_t sequence)
+{
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT leaf_info FROM Leaf \
+                      WHERE leaf_sequence=?", -1, &statement, 0);
+  sqlite3_bind_int64(statement, 1, sequence);
+  int res = sqlite3_step(statement);
+  if (res == SQLITE_ROW)
+    {
+      ndn::Buffer res_buf(sqlite3_column_blob(statement, 0), sqlite3_column_bytes(statement, 0));
+      ndn::ConstBufferPtr result = ndn::make_shared<ndn::Buffer>(res_buf);
+      sqlite3_finalize(statement);
+      return result;
+    }
+  else
+    {
+      sqlite3_finalize(statement);
+      return ndn::ConstBufferPtr();
+    }
+}
+
+
+bool
+MerkleTreeSqlite3::doesLeafInfoExist(uint64_t sequence)
+{
+  bool result = false;
+  sqlite3_stmt* statement;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT count(*) FROM Leaf WHERE leaf_sequence=?",
+                     -1, &statement, 0);
+  sqlite3_bind_int64(statement, 1, sequence);
+  int res = sqlite3_step(statement);
+  if (res == SQLITE_ROW)
+    {
+      int countAll = sqlite3_column_int(statement, 0);
+      if (countAll > 0)
+        result = true;
+    }
+  sqlite3_finalize(statement);
+  return result;
+}
+
+
+void
+MerkleTreeSqlite3::deleteLeafInfo(uint64_t sequence)
+{
+  sqlite3_stmt* stmt;
+  sqlite3_prepare_v2(m_database, "DELETE FROM Leaf WHERE leaf_sequence=?",
+                     -1, &stmt, 0);
+  sqlite3_bind_int64(stmt, 1, sequence);
+  sqlite3_step(stmt);
+  sqlite3_finalize(stmt);
+}
+
+
+void
+MerkleTreeSqlite3::getAllLeafInfo(std::map<uint64_t, ndn::ConstBufferPtr> leaves)
+{
+  sqlite3_stmt* stmt;
+  sqlite3_prepare_v2(m_database,
+                     "SELECT leaf_sequence, leaf_info FROM Leaf",
+                     -1, &stmt, 0);
+  while (sqlite3_step(stmt) == SQLITE_ROW)
+    {
+      uint64_t seq = sqlite3_column_int64(stmt, 0);
+      ndn::ConstBufferPtr buf = ndn::make_shared<ndn::Buffer>(sqlite3_column_blob(stmt, 1),
+                                                              sqlite3_column_bytes(stmt, 1));
+      leaves[seq] = buf;
+    }
+
+  sqlite3_finalize(stmt);
+}
+
+
+} // namespace nsl