diff --git a/src/contact-storage.cpp b/src/contact-storage.cpp
new file mode 100644
index 0000000..f42ec21
--- /dev/null
+++ b/src/contact-storage.cpp
@@ -0,0 +1,215 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Yingdi Yu
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Yingdi Yu <yingdi@cs.ucla.edu>
+ */
+
+#include "contact-storage.h"
+#include "exception.h"
+
+#include <string>
+#include <boost/filesystem.hpp>
+
+using namespace std;
+using namespace ndn;
+namespace fs = boost::filesystem;
+
+
+const string INIT_TC_TABLE = "\
+CREATE TABLE IF NOT EXISTS                                           \n \
+  TrustedContact(                                                    \n \
+      contact_namespace BLOB NOT NULL,                               \n \
+      contact_alias     BLOB NOT NULL,                               \n \
+      self_certificate  BLOB NOT NULL,                               \n \
+      trust_scope       BLOB NOT NULL,                               \n \
+                                                                     \
+      PRIMARY KEY (contact_namespace)                                \n \
+  );                                                                 \n \
+                                                                     \
+CREATE INDEX tc_index ON TrustedContact(contact_namespace);          \n \
+";
+
+const string INIT_NC_TABLE = "\
+CREATE TABLE IF NOT EXISTS                                           \n \
+  NormalContact(                                                     \n \
+      contact_namespace BLOB NOT NULL,                               \n \
+      contact_alias     BLOB NOT NULL,                               \n \
+      self_certificate  BLOB NOT NULL,                               \n \
+                                                                     \
+      PRIMARY KEY (contact_namespace)                                \n \
+  );                                                                 \n \
+                                                                     \
+CREATE INDEX nc_index ON NormalContact(contact_namespace);           \n \
+";
+
+ContactStorage::ContactStorage()
+{
+  fs::path chronosDir = fs::path(getenv("HOME")) / ".chronos";
+  fs::create_directories (chronosDir);
+
+  int res = sqlite3_open((chronosDir / "chronos.db").c_str (), &m_db);
+  if (res != SQLITE_OK)
+    throw LnException("Chronos DB cannot be open/created");
+
+  // Check if TrustedContact table exists
+  sqlite3_stmt *stmt;
+  sqlite3_prepare_v2 (m_db, "SELECT name FROM sqlite_master WHERE type='table' And name='TrustedContact'", -1, &stmt, 0);
+  res = sqlite3_step (stmt);
+
+  bool tcTableExist = false;
+  if (res == SQLITE_ROW)
+      tcTableExist = true;
+  sqlite3_finalize (stmt);
+
+  if(!tcTableExist)
+    {
+      char *errmsg = 0;
+      res = sqlite3_exec (m_db, INIT_TC_TABLE.c_str (), NULL, NULL, &errmsg);
+      if (res != SQLITE_OK && errmsg != 0)
+        throw LnException("Init \"error\" in TrustedContact");
+      sqlite3_finalize (stmt);
+    }
+    
+  // Check if NormalContact table exists
+  sqlite3_prepare_v2 (m_db, "SELECT name FROM sqlite_master WHERE type='table' And name='NormalContact'", -1, &stmt, 0);
+  res = sqlite3_step (stmt);
+
+  bool ncTableExist = false;
+  if (res == SQLITE_ROW)
+      ncTableExist = true;
+  sqlite3_finalize (stmt);
+
+  if(!ncTableExist)
+    {
+      char *errmsg = 0;
+      res = sqlite3_exec (m_db, INIT_NC_TABLE.c_str (), NULL, NULL, &errmsg);
+        
+      if (res != SQLITE_OK && errmsg != 0)
+        throw LnException("Init \"error\" in NormalContact");
+    }
+}
+
+void
+ContactStorage::addTrustedContact(const TrustedContact& trustedContact)
+{
+  if(doesTrustedContactExist(trustedContact.getNameSpace()))
+    throw LnException("Trusted Contact has already existed");
+  
+  sqlite3_stmt *stmt;  
+  sqlite3_prepare_v2 (m_db, 
+                      "INSERT INTO TrustedContact (contact_namespace, contact_alias, self_certificate, trust_scope) values (?, ?, ?, ?)", 
+                      -1, 
+                      &stmt, 
+                      0);
+  
+  sqlite3_bind_text(stmt, 1, trustedContact.getNameSpace().toUri().c_str(),  trustedContact.getNameSpace().toUri().size (), SQLITE_TRANSIENT);
+  sqlite3_bind_text(stmt, 2, trustedContact.getAlias().c_str(), trustedContact.getAlias().size(), SQLITE_TRANSIENT);
+  Ptr<Blob> selfCertificateBlob = trustedContact.getSelfEndorseCertificate().encodeToWire();
+  sqlite3_bind_text(stmt, 3, selfCertificateBlob->buf(), selfCertificateBlob->size(), SQLITE_TRANSIENT);
+  Ptr<Blob> trustScopeBlob = trustedContact.getTrustScopeBlob();
+  sqlite3_bind_text(stmt, 4, trustScopeBlob->buf(), trustScopeBlob->size(),SQLITE_TRANSIENT);
+
+  int res = sqlite3_step (stmt);
+  sqlite3_finalize (stmt);
+}
+  
+void
+ContactStorage::addNormalContact(const ContactItem& normalContact)
+{
+  if(doesNormalContactExist(normalContact.getNameSpace()))
+    throw LnException("Normal Contact has already existed");
+
+  sqlite3_stmt *stmt;  
+  sqlite3_prepare_v2 (m_db, 
+                      "INSERT INTO NormalContact (contact_namespace, contact_alias, self_certificate) values (?, ?, ?)", 
+                      -1, 
+                      &stmt, 
+                      0);
+
+  sqlite3_bind_text(stmt, 1, normalContact.getNameSpace().toUri().c_str(),  normalContact.getNameSpace().toUri().size (), SQLITE_TRANSIENT);
+  sqlite3_bind_text(stmt, 2, normalContact.getAlias().c_str(), normalContact.getAlias().size(), SQLITE_TRANSIENT);
+  Ptr<Blob> selfCertificateBlob = normalContact.getSelfEndorseCertificate().encodeToWire();
+  sqlite3_bind_text(stmt, 3, selfCertificateBlob->buf(), selfCertificateBlob->size(), SQLITE_TRANSIENT);
+
+  int res = sqlite3_step (stmt);
+  sqlite3_finalize (stmt);
+}
+
+bool
+ContactStorage::doesContactExist(const Name& name, bool normal)
+{
+  bool result = false;
+  
+  sqlite3_stmt *stmt;
+  if(normal)
+    sqlite3_prepare_v2 (m_db, "SELECT count(*) FROM NormalContact WHERE contact_namespace=?", -1, &stmt, 0);
+  else
+    sqlite3_prepare_v2 (m_db, "SELECT count(*) FROM TrustedContact WHERE contact_namespace=?", -1, &stmt, 0);
+  sqlite3_bind_text(stmt, 1, name.toUri().c_str(), name.toUri().size(), SQLITE_TRANSIENT);
+
+  int res = sqlite3_step (stmt);
+    
+  if (res == SQLITE_ROW)
+    {
+      int countAll = sqlite3_column_int (stmt, 0);
+      if (countAll > 0)
+        result = true;
+    } 
+  sqlite3_finalize (stmt); 
+  return result;
+}
+
+vector<Ptr<TrustedContact> >
+ContactStorage::getAllTrustedContacts() const
+{
+  vector<Ptr<TrustedContact> > trustedContacts;
+
+  sqlite3_stmt *stmt;
+  sqlite3_prepare_v2 (m_db, 
+                      "SELECT contact_alias, self_certificate, trust_scope FROM TrustedContact", 
+                      -1, 
+                      &stmt, 
+                      0);
+  
+  while( sqlite3_step (stmt) == SQLITE_ROW)
+    {
+      string alias(reinterpret_cast<const char *>(sqlite3_column_text(stmt, 0)), sqlite3_column_bytes (stmt, 0));
+      Ptr<Blob> certBlob = Ptr<Blob>(new Blob(reinterpret_cast<const char *>(sqlite3_column_text(stmt, 1)), sqlite3_column_bytes (stmt, 1)));
+      Ptr<Data> certData = Data::decodeFromWire(certBlob);
+      EndorseCertificate endorseCertificate(*certData);
+      string trustScope(reinterpret_cast<const char *>(sqlite3_column_text(stmt, 2)), sqlite3_column_bytes (stmt, 2));
+
+      trustedContacts.push_back(Ptr<TrustedContact>(new TrustedContact(endorseCertificate, trustScope, alias)));      
+    }
+
+  return trustedContacts;
+}
+
+vector<Ptr<ContactItem> >
+ContactStorage::getAllNormalContacts() const
+{
+  vector<Ptr<ContactItem> > normalContacts;
+
+  sqlite3_stmt *stmt;
+  sqlite3_prepare_v2 (m_db, 
+                      "SELECT contact_alias, self_certificate FROM NormalContact", 
+                      -1, 
+                      &stmt, 
+                      0);
+  
+  while( sqlite3_step (stmt) == SQLITE_ROW)
+    {
+      string alias(reinterpret_cast<const char *>(sqlite3_column_text(stmt, 0)), sqlite3_column_bytes (stmt, 0));
+      Ptr<Blob> certBlob = Ptr<Blob>(new Blob(reinterpret_cast<const char *>(sqlite3_column_text(stmt, 1)), sqlite3_column_bytes (stmt, 1)));
+      Ptr<Data> certData = Data::decodeFromWire(certBlob);
+      EndorseCertificate endorseCertificate(*certData);
+
+      normalContacts.push_back(Ptr<ContactItem>(new ContactItem(endorseCertificate, alias)));      
+    }
+  
+  return normalContacts;
+}