diff --git a/tools/ndnsec-dsk-gen.hpp b/tools/ndnsec-dsk-gen.hpp
new file mode 100644
index 0000000..b7d95e8
--- /dev/null
+++ b/tools/ndnsec-dsk-gen.hpp
@@ -0,0 +1,159 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ * BSD license, See the LICENSE file for more information
+ * Author: Yingdi Yu <yingdi@cs.ucla.edu>
+ */
+
+#ifndef NDNSEC_DSK_GEN_HPP
+#define NDNSEC_DSK_GEN_HPP
+
+#include "ndnsec-util.hpp"
+
+int 
+ndnsec_dsk_gen(int argc, char** argv)
+{
+  using namespace ndn;
+  namespace po = boost::program_options;
+
+  std::string identityName;
+  char keyType = 'r';
+  int keySize = 2048;
+
+  po::options_description desc("General Usage\n  ndnsec dsk-gen [-h] identity\nGeneral options");
+  desc.add_options()
+    ("help,h", "produce help message")
+    ("identity,i", po::value<std::string>(&identityName), "identity name, for example, /ndn/ucla.edu/alice")
+    // ("type,t", po::value<char>(&keyType)->default_value('r'), "optional, key type, r for RSA key (default)")
+    // ("size,s", po::value<int>(&keySize)->default_value(2048), "optional, key size, 2048 (default)")
+    ;
+
+  po::positional_options_description p;
+  p.add("identity", 1);
+
+  po::variables_map vm;
+  po::store(po::command_line_parser(argc, argv).options(desc).positional(p).run(), vm);
+  po::notify(vm);
+
+  if (vm.count("help"))
+    {
+      std::cerr << desc << std::endl;
+      return 0;
+    }
+
+  if (0 == vm.count("identity"))
+    {
+      std::cerr << "identity must be specified" << std::endl;
+      std::cerr << desc << std::endl;
+      return 1;
+    }
+
+  shared_ptr<IdentityCertificate> kskCert;
+  Name signingCertName;
+  try
+    {
+      KeyChain keyChain;
+
+      Name defaultCertName = keyChain.getDefaultCertificateNameForIdentity(identityName);
+      bool isDefaultDsk = false;
+      if(defaultCertName.get(-3).toEscapedString().substr(0,4) == "dsk-")
+        isDefaultDsk = true;
+
+      if(isDefaultDsk)
+        {
+          shared_ptr<IdentityCertificate> dskCert = keyChain.getCertificate(defaultCertName);
+          SignatureSha256WithRsa sha256sig(dskCert->getSignature());
+
+          Name keyLocatorName = sha256sig.getKeyLocator().getName(); // will throw exception if keylocator is absent or it is not a name
+
+          Name kskName = IdentityCertificate::certificateNameToPublicKeyName(keyLocatorName);
+          Name kskCertName = keyChain.getDefaultCertificateNameForKey(kskName);
+          signingCertName = kskCertName;
+          kskCert = keyChain.getCertificate(kskCertName);
+        }
+      else
+        {
+          signingCertName = defaultCertName;
+          kskCert = keyChain.getCertificate(defaultCertName);
+        }
+    }
+  catch(SignatureSha256WithRsa::Error& e)
+    {
+      std::cerr << "ERROR: " << e.what() << std::endl;
+      return 1;
+    }
+  catch(KeyLocator::Error& e)
+    {
+      std::cerr << "ERROR: " << e.what() << std::endl;
+      return 1;
+    }
+  catch(SecPublicInfo::Error& e)
+    {
+      std::cerr << "ERROR: " << e.what() << std::endl;
+      return 1;
+    }
+
+  if(!static_cast<bool>(kskCert))
+    {
+      std::cerr << "ERROR: no KSK certificate." << std::endl;
+      return 1;
+    }
+
+  try
+    {
+      KeyChain keyChain;
+      Name newKeyName;
+      switch(keyType)
+        {
+        case 'r':
+          {
+            newKeyName = keyChain.generateRSAKeyPair(Name(identityName), false, keySize);
+            if(0 == newKeyName.size())
+              {
+                std::cerr << "fail to generate key!" << std::endl;
+                return 1;
+              }
+            break;
+          }
+        default:
+          std::cerr << "Unrecongized key type" << "\n";
+          std::cerr << desc << std::endl;
+          return 1;
+        }
+    
+      Name certName = newKeyName.getPrefix(-1);
+      certName.append("KEY").append(newKeyName.get(-1)).append("ID-CERT").appendVersion();
+
+      shared_ptr<IdentityCertificate> certificate = make_shared<IdentityCertificate>();
+      certificate->setName(certName);
+      certificate->setNotBefore(kskCert->getNotBefore());
+      certificate->setNotAfter(kskCert->getNotAfter());
+
+      certificate->setPublicKeyInfo(*keyChain.getPublicKey(newKeyName));
+
+      const std::vector<CertificateSubjectDescription>& subList = kskCert->getSubjectDescriptionList();
+      std::vector<CertificateSubjectDescription>::const_iterator it = subList.begin();
+      for(; it != subList.end(); it++)
+        certificate->addSubjectDescription(*it);
+      
+      certificate->encode();
+
+      keyChain.sign(*certificate, signingCertName);
+
+      keyChain.addCertificateAsIdentityDefault(*certificate);
+
+      return 0;
+    }
+  catch(SecPublicInfo::Error& e)
+    {
+      std::cerr << "ERROR: " << e.what() << std::endl;
+      return 1;
+    }
+  catch(SecTpm::Error& e)
+    {
+      std::cerr << "ERROR: " << e.what() << std::endl;
+      return 1;
+    }
+}
+
+#endif //NDNSEC_DSK_GEN_HPP