diff --git a/ndn-cpp/helpers/hash.cc b/ndn-cpp/helpers/hash.cc
new file mode 100644
index 0000000..0ecf927
--- /dev/null
+++ b/ndn-cpp/helpers/hash.cc
@@ -0,0 +1,130 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Alexander Afanasyev
+ *                     Zhenkai Zhu
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ *         Zhenkai Zhu <zhenkai@cs.ucla.edu>
+ */
+
+#include "hash.h"
+#include "ndn-cpp/helpers/uri.h"
+
+#include <boost/lexical_cast.hpp>
+#include <openssl/evp.h>
+#include <fstream>
+
+using namespace boost;
+using namespace std;
+
+// Other options: VP_md2, EVP_md5, EVP_sha, EVP_sha1, EVP_sha256, EVP_dss, EVP_dss1, EVP_mdc2, EVP_ripemd160
+#define HASH_FUNCTION EVP_sha256
+
+namespace ndn
+{
+
+std::ostream &
+operator << (std::ostream &os, const Hash &hash)
+{
+  if (hash.m_length == 0)
+    return os;
+
+  ostreambuf_iterator<char> out_it (os); // ostream iterator
+  // need to encode to base64
+  copy (detail::string_from_binary (reinterpret_cast<const char*> (hash.m_buf)),
+        detail::string_from_binary (reinterpret_cast<const char*> (hash.m_buf+hash.m_length)),
+        out_it);
+
+  return os;
+}
+
+std::string
+Hash::shortHash () const
+{
+  return lexical_cast<string> (*this).substr (0, 10);
+}
+
+
+unsigned char Hash::_origin = 0;
+HashPtr Hash::Origin(new Hash(&Hash::_origin, sizeof(unsigned char)));
+
+HashPtr
+Hash::FromString (const std::string &hashInTextEncoding)
+{
+  HashPtr retval = make_shared<Hash> (reinterpret_cast<void*> (0), 0);
+
+  if (hashInTextEncoding.size () == 0)
+    {
+      return retval;
+    }
+
+  if (hashInTextEncoding.size () > EVP_MAX_MD_SIZE * 2)
+    {
+      cerr << "Input hash is too long. Returning an empty hash" << endl;
+      return retval;
+    }
+
+  retval->m_buf = new unsigned char [EVP_MAX_MD_SIZE];
+
+  unsigned char *end = copy (detail::string_to_binary (hashInTextEncoding.begin ()),
+                             detail::string_to_binary (hashInTextEncoding.end ()),
+                             retval->m_buf);
+
+  retval->m_length = end - retval->m_buf;
+
+  return retval;
+}
+
+HashPtr
+Hash::FromFileContent (const char *filename)
+{
+  HashPtr retval = make_shared<Hash> (reinterpret_cast<void*> (0), 0);
+  retval->m_buf = new unsigned char [EVP_MAX_MD_SIZE];
+
+  EVP_MD_CTX *hash_context = EVP_MD_CTX_create ();
+  EVP_DigestInit_ex (hash_context, HASH_FUNCTION (), 0);
+
+  ifstream iff (filename, std::ios::in | std::ios::binary);
+  while (iff.good ())
+    {
+      char buf[1024];
+      iff.read (buf, 1024);
+      EVP_DigestUpdate (hash_context, buf, iff.gcount ());
+    }
+
+  retval->m_buf = new unsigned char [EVP_MAX_MD_SIZE];
+
+  EVP_DigestFinal_ex (hash_context,
+                      retval->m_buf, &retval->m_length);
+
+  EVP_MD_CTX_destroy (hash_context);
+
+  return retval;
+}
+
+HashPtr
+Hash::FromBytes (const ndn::Bytes &bytes)
+{
+  HashPtr retval = make_shared<Hash> (reinterpret_cast<void*> (0), 0);
+  retval->m_buf = new unsigned char [EVP_MAX_MD_SIZE];
+
+  EVP_MD_CTX *hash_context = EVP_MD_CTX_create ();
+  EVP_DigestInit_ex (hash_context, HASH_FUNCTION (), 0);
+
+  // not sure whether it's bad to do so if bytes.size is huge
+  EVP_DigestUpdate(hash_context, ndn::head(bytes), bytes.size());
+
+  retval->m_buf = new unsigned char [EVP_MAX_MD_SIZE];
+
+  EVP_DigestFinal_ex (hash_context,
+                      retval->m_buf, &retval->m_length);
+
+  EVP_MD_CTX_destroy (hash_context);
+
+  return retval;
+}
+
+} // ndn