security: Add signing and validating process

Change-Id: Ic9edfcf56f044821e167d7e49b75a9023b67fbcd
diff --git a/src/hello-protocol.hpp b/src/hello-protocol.hpp
index fc84457..ac0433a 100644
--- a/src/hello-protocol.hpp
+++ b/src/hello-protocol.hpp
@@ -58,11 +58,17 @@
   processInterestTimedOut(const ndn::Interest& interest);
 
   void
-  processContent(const ndn::Interest& interest, const ndn::Data& data);
+  onContent(const ndn::Interest& interest, const ndn::Data& data);
+
+  void
+  onContentValidated(const ndn::shared_ptr<const ndn::Data>& data);
+
+  void
+  onContentValidationFailed(const ndn::shared_ptr<const ndn::Data>& data,
+                            const std::string& msg);
 
 private:
   Nlsr& m_nlsr;
-  ndn::KeyChain m_keyChain;
   static const std::string INFO_COMPONENT;
 };