diff --git a/tests/unit-tests/security/transform.t.cpp b/tests/unit-tests/security/transform.t.cpp
index ea2fa0f..f0a6b27 100644
--- a/tests/unit-tests/security/transform.t.cpp
+++ b/tests/unit-tests/security/transform.t.cpp
@@ -58,6 +58,9 @@
 
   transform::Base64Decode* base64Decode = nullptr;
   BOOST_CHECK(base64Decode == nullptr);
+
+  transform::DigestFilter* digestFilter = nullptr;
+  BOOST_CHECK(digestFilter == nullptr);
 }
 
 BOOST_AUTO_TEST_SUITE_END() // TestTransform
diff --git a/tests/unit-tests/security/transform/digest-filter.t.cpp b/tests/unit-tests/security/transform/digest-filter.t.cpp
new file mode 100644
index 0000000..f00599c
--- /dev/null
+++ b/tests/unit-tests/security/transform/digest-filter.t.cpp
@@ -0,0 +1,149 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "security/transform/buffer-source.hpp"
+#include "security/transform/step-source.hpp"
+#include "security/transform/digest-filter.hpp"
+#include "security/transform/stream-sink.hpp"
+#include "encoding/buffer-stream.hpp"
+
+#include "boost-test.hpp"
+
+namespace ndn {
+namespace security {
+namespace transform {
+namespace tests {
+
+BOOST_AUTO_TEST_SUITE(Security)
+BOOST_AUTO_TEST_SUITE(Transform)
+BOOST_AUTO_TEST_SUITE(TestDigestFilter)
+
+BOOST_AUTO_TEST_CASE(Basic)
+{
+  uint8_t in[128] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+  };
+
+  uint8_t out[] = {
+    0x3e, 0x14, 0xfd, 0x66, 0x9a, 0x79, 0x80, 0x65,
+    0xc4, 0x0d, 0x61, 0xf8, 0x6a, 0xc7, 0x98, 0x29,
+    0xc0, 0x6b, 0x90, 0x8f, 0xbb, 0x19, 0xa0, 0x85,
+    0xf7, 0xfa, 0x7b, 0x2d, 0xd6, 0x8c, 0xd5, 0xa3
+  };
+
+  OBufferStream os;
+  bufferSource(in, sizeof(in)) >> digestFilter(DIGEST_ALGORITHM_SHA256) >> streamSink(os);
+
+  ConstBufferPtr buf = os.buf();
+  BOOST_CHECK_EQUAL_COLLECTIONS(out, out + sizeof(out), buf->begin(), buf->end());
+}
+
+BOOST_AUTO_TEST_CASE(StepByStep)
+{
+  uint8_t in[128] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+  };
+
+  uint8_t out[] = {
+    0x3e, 0x14, 0xfd, 0x66, 0x9a, 0x79, 0x80, 0x65,
+    0xc4, 0x0d, 0x61, 0xf8, 0x6a, 0xc7, 0x98, 0x29,
+    0xc0, 0x6b, 0x90, 0x8f, 0xbb, 0x19, 0xa0, 0x85,
+    0xf7, 0xfa, 0x7b, 0x2d, 0xd6, 0x8c, 0xd5, 0xa3
+  };
+
+  StepSource source;
+  OBufferStream os;
+  source >> digestFilter(DIGEST_ALGORITHM_SHA256) >> streamSink(os);
+  source.write(in, 32);
+  source.write(in + 32, 1);
+  source.write(in + 33, 2);
+  source.write(in + 35, 3);
+  source.write(in + 38, 26);
+  source.write(in + 64, 64);
+  source.end();
+
+  ConstBufferPtr buf = os.buf();
+  BOOST_CHECK_EQUAL_COLLECTIONS(out, out + sizeof(out), buf->begin(), buf->end());
+}
+
+BOOST_AUTO_TEST_CASE(EmptyInput)
+{
+  uint8_t out[] = {
+    0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
+    0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
+    0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
+    0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55
+  };
+
+  OBufferStream os;
+  StepSource source;
+  source >> digestFilter(DIGEST_ALGORITHM_SHA256) >> streamSink(os);
+  source.end();
+
+  ConstBufferPtr buf = os.buf();
+  BOOST_CHECK_EQUAL_COLLECTIONS(out, out + sizeof(out), buf->begin(), buf->end());
+}
+
+BOOST_AUTO_TEST_CASE(Error)
+{
+  OBufferStream os;
+  BOOST_REQUIRE_THROW(stepSource() >> digestFilter(DIGEST_ALGORITHM_NONE) >> streamSink(os),
+                      transform::Error);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // TestDigestFilter
+BOOST_AUTO_TEST_SUITE_END() // Transform
+BOOST_AUTO_TEST_SUITE_END() // Security
+
+} // namespace tests
+} // namespace transform
+} // namespace security
+} // namespace ndn