diff --git a/ndn-cpp/helpers/hash.h b/ndn-cpp/helpers/hash.h
new file mode 100644
index 0000000..1652f2b
--- /dev/null
+++ b/ndn-cpp/helpers/hash.h
@@ -0,0 +1,162 @@
+/* -*- 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>
+ */
+
+#ifndef NDN_HASH_H
+#define NDN_HASH_H
+
+#include <string.h>
+#include <iostream>
+#include <boost/shared_ptr.hpp>
+#include <boost/exception/all.hpp>
+
+#include "ndn-cpp/common.h"
+
+namespace ndn
+{
+
+class Hash;
+typedef boost::shared_ptr<Hash> HashPtr;
+
+class Hash
+{
+public:
+  static unsigned char _origin;
+  static HashPtr Origin;
+
+  Hash ()
+    : m_buf(0)
+    , m_length(0)
+  {
+  }
+
+  Hash (const void *buf, unsigned int length)
+    : m_length (length)
+  {
+    if (m_length != 0)
+      {
+        m_buf = new unsigned char [length];
+        memcpy (m_buf, buf, length);
+      }
+  }
+
+  Hash (const Hash &otherHash)
+  : m_length (otherHash.m_length)
+  {
+    if (m_length != 0)
+      {
+        m_buf = new unsigned char [m_length];
+        memcpy (m_buf, otherHash.m_buf, otherHash.m_length);
+      }
+  }
+
+  static HashPtr
+  FromString (const std::string &hashInTextEncoding);
+
+  static HashPtr
+  FromFileContent (const char *fileName);
+
+  static HashPtr
+  FromBytes (const ndn::Bytes &bytes);
+
+  ~Hash ()
+  {
+    if (m_length != 0)
+      delete [] m_buf;
+  }
+
+  Hash &
+  operator = (const Hash &otherHash)
+  {
+    if (m_length != 0)
+      delete [] m_buf;
+
+    m_length = otherHash.m_length;
+    if (m_length != 0)
+      {
+        m_buf = new unsigned char [m_length];
+        memcpy (m_buf, otherHash.m_buf, otherHash.m_length);
+      }
+    return *this;
+  }
+
+  bool
+  IsZero () const
+  {
+    return m_length == 0 ||
+      (m_length == 1 && m_buf[0] == 0);
+  }
+
+  bool
+  operator == (const Hash &otherHash) const
+  {
+    if (m_length != otherHash.m_length)
+      return false;
+
+    return memcmp (m_buf, otherHash.m_buf, m_length) == 0;
+  }
+
+  bool operator < (const Hash &otherHash) const
+  {
+    if (m_length < otherHash.m_length)
+      return true;
+
+    if (m_length > otherHash.m_length)
+      return false;
+
+    for (unsigned int i = 0; i < m_length; i++)
+      {
+        if (m_buf [i] < otherHash.m_buf [i])
+          return true;
+
+        if (m_buf [i] > otherHash.m_buf [i])
+          return false;
+
+        // if equal, continue
+      }
+
+    return false;
+  }
+
+  const void *
+  GetHash () const
+  {
+    return m_buf;
+  }
+
+  unsigned int
+  GetHashBytes () const
+  {
+    return m_length;
+  }
+
+  std::string
+  shortHash () const;
+
+private:
+  unsigned char *m_buf;
+  unsigned int m_length;
+
+  friend std::ostream &
+  operator << (std::ostream &os, const Hash &digest);
+};
+
+namespace Error {
+struct HashConversion : virtual boost::exception, virtual std::exception { };
+}
+
+
+std::ostream &
+operator << (std::ostream &os, const Hash &digest);
+
+}
+
+#endif // NDN_HASH_H