diff --git a/src/security/v2/validation-callback.hpp b/src/security/v2/validation-callback.hpp
new file mode 100644
index 0000000..7ef4564
--- /dev/null
+++ b/src/security/v2/validation-callback.hpp
@@ -0,0 +1,58 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 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.
+ */
+
+#ifndef NDN_SECURITY_V2_VALIDATION_CALLBACK_HPP
+#define NDN_SECURITY_V2_VALIDATION_CALLBACK_HPP
+
+#include "../../interest.hpp"
+#include "../../data.hpp"
+#include "../security-common.hpp"
+#include "validation-error.hpp"
+
+namespace ndn {
+namespace security {
+namespace v2 {
+
+/**
+ * @brief Callback to report a successful Data validation.
+ */
+typedef function<void(const Data& data)> DataValidationSuccessCallback;
+
+/**
+ * @brief Callback to report a failed Data validation.
+ */
+typedef function<void(const Data& data, const ValidationError& error)> DataValidationFailureCallback;
+
+/**
+ * @brief Callback to report a successful Interest validation.
+ */
+typedef function<void(const Interest& interest)> InterestValidationSuccessCallback;
+
+/**
+ * @brief Callback to report a failed Interest validation.
+ */
+typedef function<void(const Interest& interest, const ValidationError& error)> InterestValidationFailureCallback;
+
+} // namespace v2
+} // namespace security
+} // namespace ndn
+
+#endif // NDN_SECURITY_V2_VALIDATION_CALLBACK_HPP