diff --git a/src/invitation.cpp b/src/invitation.cpp
new file mode 100644
index 0000000..9495cec
--- /dev/null
+++ b/src/invitation.cpp
@@ -0,0 +1,70 @@
+/* -*- 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 "invitation.h"
+
+#include <ndn-cpp-dev/security/identity-certificate.hpp>
+#include <ndn-cpp-dev/security/signature-sha256-with-rsa.hpp>
+
+#include "logging.h"
+
+using namespace std;
+using namespace ndn;
+
+INIT_LOGGER("Invitation");
+
+
+namespace chronos{
+
+const size_t  Invitation::NAME_SIZE_MIN  = 9;
+const size_t  Invitation::INVITEE_START  = 4;
+const ssize_t Invitation::SIGNATURE      = -1;
+const ssize_t Invitation::KEY_LOCATOR    = -2;
+const ssize_t Invitation::TIMESTAMP      = -3;
+const ssize_t Invitation::INVITER_PREFIX = -4;
+const ssize_t Invitation::CHATROOM       = -5;
+const Name    Invitation::INVITATION_PREFIX("/ndn/broadcast/chronos/chat-invitation");
+
+
+Invitation::Invitation(const Name& interestName)
+{
+  size_t nameSize = interestName.size();
+
+  if(nameSize < NAME_SIZE_MIN)
+    throw Error("Wrong Invitation Name: Wrong length"); 
+ 
+  if(!INVITATION_PREFIX.isPrefixOf(interestName))
+    throw Error("Wrong Invitation Name: Wrong invitation prefix");
+
+  m_interestName = interestName.getPrefix(-3);
+  m_inviterRoutingPrefix.wireDecode(interestName.get(INVITER_PREFIX).blockFromValue());
+  m_chatroom.wireDecode(interestName.get(CHATROOM).blockFromValue());
+  m_inviteeNameSpace = interestName.getSubName(INVITEE_START, nameSize - NAME_SIZE_MIN);  
+}
+
+Invitation::Invitation(const Name &inviteeNameSpace,
+                       const Name &chatroom,
+                       const Name &inviterRoutingPrefix)
+  : m_inviteeNameSpace(inviteeNameSpace)
+  , m_chatroom(chatroom)
+  , m_inviterRoutingPrefix(inviterRoutingPrefix)
+{  
+  m_interestName = INVITATION_PREFIX;
+  m_interestName.append(inviteeNameSpace).append(chatroom.wireEncode()).append(inviterRoutingPrefix.wireEncode());
+}
+
+Invitation::Invitation(const Invitation& invitation)
+  : m_interestName(invitation.m_interestName)
+  , m_inviteeNameSpace(invitation.m_inviteeNameSpace)
+  , m_chatroom(invitation.m_chatroom)
+  , m_inviterRoutingPrefix(invitation.m_inviterRoutingPrefix)
+{}
+
+}//chronos