diff --git a/src/invitation-policy-manager.cpp b/src/invitation-policy-manager.cpp
new file mode 100644
index 0000000..3c87c46
--- /dev/null
+++ b/src/invitation-policy-manager.cpp
@@ -0,0 +1,184 @@
+/* -*- 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-policy-manager.h"
+#include "logging.h"
+
+using namespace std;
+using namespace ndn;
+using namespace ndn::security;
+
+INIT_LOGGER("InvitationPolicyManager");
+
+InvitationPolicyManager::InvitationPolicyManager(const int & stepLimit,
+						 Ptr<CertificateCache> certificateCache,
+						 Name signingIdentity)
+  : m_stepLimit(stepLimit)
+  , m_certificateCache(certificateCache)
+  , m_localPrefixRegex(Ptr<Regex>(new Regex("^<local><ndn><prefix><><>$")))
+{
+  m_invitationDataRule = Ptr<IdentityPolicyRule>(new IdentityPolicyRule("^<ndn><broadcast><chronos><invitation>([^<chatroom>]*)<chatroom>", 
+									"^([^<KEY>]*)<KEY><DSK-.*><ID-CERT>$", 
+									"==", "\\1", "\\1", true));
+  
+  m_dskRule = Ptr<IdentityPolicyRule>(new IdentityPolicyRule("^([^<KEY>]*)<KEY><DSK-.*><ID-CERT>$", 
+							     "^([^<KEY>]*)<KEY>(<>*)<KSK-.*><ID-CERT>$", 
+							     "==", "\\1", "\\1\\2", true));
+  m_signingCertificateRegex = Ptr<Regex>(new Regex("^<ndn><broadcast><chronos><invitation>([^<chatroom>]*)<chatroom>", "\\1"));
+}
+
+bool 
+InvitationPolicyManager::skipVerifyAndTrust (const Data & data)
+{
+  if(m_localPrefixRegex->match(data.getName()))
+    return true;
+  
+  return false;
+}
+
+bool
+InvitationPolicyManager::requireVerify (const Data & data)
+{
+  if(m_invitationDataRule->matchDataName(data))
+    return true;
+
+  if(m_dskRule->matchDataName(data))
+    return true;
+
+  return false;
+}
+
+Ptr<ValidationRequest>
+InvitationPolicyManager::checkVerificationPolicy(Ptr<Data> data, 
+						 const int & stepCount, 
+						 const DataCallback& verifiedCallback,
+						 const UnverifiedCallback& unverifiedCallback)
+{
+  if(m_stepLimit == stepCount)
+    {
+      _LOG_DEBUG("reach the maximum steps of verification");
+      unverifiedCallback(data);
+      return NULL;
+    }
+
+  Ptr<const signature::Sha256WithRsa> sha256sig = boost::dynamic_pointer_cast<const signature::Sha256WithRsa> (data->getSignature());    
+
+  if(KeyLocator::KEYNAME != sha256sig->getKeyLocator().getType())
+    {
+      unverifiedCallback(data);
+      return NULL;
+    }
+
+  const Name & keyLocatorName = sha256sig->getKeyLocator().getKeyName();
+
+  if(m_invitationDataRule->satisfy(*data))
+    {
+      Ptr<const IdentityCertificate> trustedCert = m_certificateCache->getCertificate(keyLocatorName);
+      
+      if(NULL != trustedCert){
+	if(verifySignature(*data, trustedCert->getPublicKeyInfo()))
+	  verifiedCallback(data);
+	else
+	  unverifiedCallback(data);
+
+	return NULL;
+      }
+      else{
+	_LOG_DEBUG("KeyLocator has not been cached and validated!");
+
+	DataCallback recursiveVerifiedCallback = boost::bind(&InvitationPolicyManager::onCertificateVerified, 
+							     this, 
+							     _1, 
+							     data, 
+							     verifiedCallback, 
+							     unverifiedCallback);
+
+	UnverifiedCallback recursiveUnverifiedCallback = boost::bind(&InvitationPolicyManager::onCertificateUnverified, 
+								     this, 
+								     _1, 
+								     data, 
+								     unverifiedCallback);
+
+
+	Ptr<Interest> interest = Ptr<Interest>(new Interest(sha256sig->getKeyLocator().getKeyName()));
+	
+	Ptr<ValidationRequest> nextStep = Ptr<ValidationRequest>(new ValidationRequest(interest, 
+										       recursiveVerifiedCallback,
+										       recursiveUnverifiedCallback,
+										       0,
+										       stepCount + 1)
+								 );
+	return nextStep;
+      }
+    }
+
+  if(m_dskRule->satisfy(*data))
+    {
+      Ptr<IdentityCertificate> trustedCert;
+      if(m_trustAnchors.end() != m_trustAnchors.find(keyLocatorName))
+	trustedCert = m_trustAnchors[keyLocatorName];
+      else
+	{
+	  unverifiedCallback(data);
+	  return NULL;
+	}
+
+      if(verifySignature(*data, trustedCert->getPublicKeyInfo()))
+	verifiedCallback(data);
+      else
+	unverifiedCallback(data);
+
+      return NULL;	
+    }
+}
+
+void 
+InvitationPolicyManager::onCertificateVerified(Ptr<Data> certData, 
+					       Ptr<Data> originalData,
+					       const DataCallback& verifiedCallback, 
+					       const UnverifiedCallback& unverifiedCallback)
+{
+  IdentityCertificate certificate(*certData);
+
+  if(verifySignature(*originalData, certificate.getPublicKeyInfo()))
+    verifiedCallback(originalData);
+  else
+    unverifiedCallback(originalData);
+
+  return NULL;
+}
+
+void
+InvitationPolicyManager::onCertificateUnverified(Ptr<Data> certData, 
+						 Ptr<Data> originalData,
+						 const UnverifiedCallback& unverifiedCallback)
+{ unverifiedCallback(originalData); }
+
+bool 
+InvitationPolicyManager::checkSigningPolicy(const Name & dataName, const Name & certificateName)
+{
+  return m_invitationDataRule->satisfy(dataName, certificateName);
+}
+
+Name 
+InvitationPolicyManager::inferSigningIdentity(const Name & dataName)
+{
+  if(m_signingCertificateRegex->match(data))
+    return m_signingCertificateRegex->expand();
+  else
+    return Name();
+}
+
+void
+InvitationPolicyManager::addTrustAnchor(Ptr<IdentityCertificate> ksk)
+{
+  Name name = ksk->getName();    
+  m_cache.insert(pair <Name, Ptr<IdentityCertificate> > (name, ksk));
+}
diff --git a/src/invitation-policy-manager.h b/src/invitation-policy-manager.h
new file mode 100644
index 0000000..5684138
--- /dev/null
+++ b/src/invitation-policy-manager.h
@@ -0,0 +1,103 @@
+/* -*- 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>
+ */
+
+#ifndef INVITATION_POLICY_MANAGER_H
+#define INVITATION_POLICY_MANAGER_H
+
+#include <ndn.cxx/security/policy/policy-manager.h>
+#include <ndn.cxx/security/policy/identity-policy-rule.h>
+#include <map>
+
+class InvitationPolicyManager : ndn::security::PolicyManager
+{
+public:
+  InvitationPolicyManager(const int & stepLimit,                        
+                          ndn::Ptr<ndn::security::CertificateCache> certificateCache,
+                          ndn::Name signingIdentity);
+
+  ~InvitationPolicyManager()
+  {}
+
+  /**
+   * @brief check if the received data packet can escape from verification
+   * @param data the received data packet
+   * @return true if the data does not need to be verified, otherwise false
+   */
+  bool 
+  skipVerifyAndTrust (const ndn::Data & data);
+
+  /**
+   * @brief check if PolicyManager has the verification rule for the received data
+   * @param data the received data packet
+   * @return true if the data must be verified, otherwise false
+   */
+  bool
+  requireVerify (const ndn::Data & data);
+
+  /**
+   * @brief check whether received data packet complies with the verification policy, and get the indication of next verification step
+   * @param data the received data packet
+   * @param stepCount the number of verification steps that have been done, used to track the verification progress
+   * @param verifiedCallback the callback function that will be called if the received data packet has been validated
+   * @param unverifiedCallback the callback function that will be called if the received data packet cannot be validated
+   * @return the indication of next verification step, NULL if there is no further step
+   */
+  Ptr<ValidationRequest>
+  checkVerificationPolicy(ndn::Ptr<ndn::Data> data, 
+                          const int & stepCount, 
+                          const ndn::DataCallback& verifiedCallback,
+                          const ndn::UnverifiedCallback& unverifiedCallback);
+
+    
+  /**
+   * @brief check if the signing certificate name and data name satify the signing policy 
+   * @param dataName the name of data to be signed
+   * @param certificateName the name of signing certificate
+   * @return true if the signing certificate can be used to sign the data, otherwise false
+   */
+  bool 
+  checkSigningPolicy(const ndn::Name & dataName, const ndn::Name & certificateName);
+  
+  /**
+   * @brief Infer signing identity name according to policy, if the signing identity cannot be inferred, it should return empty name
+   * @param dataName, the name of data to be signed
+   * @return the signing identity. 
+   */
+  Name 
+  inferSigningIdentity(const ndn::Name & dataName);
+
+  
+  void
+  addTrustAnchor(ndn::Ptr<ndn::security::IdentityCertificate> ksk);
+
+private:
+  void 
+  onCertificateVerified(ndn::Ptr<ndn::Data> certData, 
+                        ndn::Ptr<ndn::Data> originalData,
+                        const ndn::DataCallback& verifiedCallback, 
+                        const ndn::UnverifiedCallback& unverifiedCallback);
+
+  void
+  onCertificateUnverified(ndn::Ptr<ndn::Data> certData, 
+                          ndn::Ptr<ndn::Data> originalData,
+                          const ndn::UnverifiedCallback& unverifiedCallback);
+
+private:
+  int m_stepLimit;
+  ndn::Ptr<ndn::security::CertificateCache> m_certificateCache;
+  ndn::Ptr<ndn::Regex> m_localPrefixRegex;
+  ndn::Ptr<ndn::IdentityPolicyRule> m_invitationDataRule;
+  ndn::Ptr<ndn::IdentityPolicyRule> m_dskRule;
+  ndn::Ptr<ndn::Regex> m_signingCertificateRegex;
+  std::map<ndn::Name, ndn::Ptr<ndn::security::IdentityCertificate> > m_trustAnchors;
+  
+};
+
+#endif