Communication over the Internet using Covert Channels

A covert channel is a mechanism that can be used to communicate data across network or between processes within the system by violating the networks/ systems security policy and in a manner that goes unnoticed. An effective covert channel is the one that is undetectable by the adversary and can provide high degree of privacy. The goal of the covert channel is to communicate data from one host to another host in a way that receiving host can detect the data but the eavesdropper won’t even get the hint that some secret data was being communicated. This paper describes two types of covert channels: covert storage channel and covert timing channel and shows how two parties can communicate over the internet using these channels without being detected by the modern security tools.