Behavioral analysis of transport layer based hybrid covert channel

Abstract

Covert Channels are malicious conversation in a legitimate secured network communication that violates the security policies laid down. Covert channels are hidden, unintended design in the legitimate communication whose motto is to leak information. Trapdoors are unintended design with a communication system that exists in network covert channels as a part of rudimentary protocols. Subliminal channel, a variant of covert channel works similarly as network covert channel except that trapdoor is set in cryptographic algorithm. A composition of covert channel with subliminal channel is the Hybrid Channel or Hybrid Covert Channel. Hybrid Covert Channels are a major threat for security which is clearly unacceptable in presence of secured network communication. The objective of the present paper is to make microscopic analysis of behavior of hybrid covert channel with a clearly understanding of theoretical literatures of composed covert channels. Paper proposes practical implementation of transport layer based hybrid covert channeling based on TCP and SSL. © 2010 Springer-Verlag Berlin Heidelberg.