Stealthy Protocols: Metrics and Open Problems

This paper is a survey of both methods that could be used to support stealthy communication over both wired and wireless networks and techniques for evaluating them. By stealthy communication we mean communication using channels that guarantee that the nature of the communication, or even the fact that communication is taking place at all, is hidden. Although stealthy communication and information hiding have been studied from a number of different points of view, e.g. image steganography, network covert channels, and covert wireless communication, not much has been done to tie these different threads together and attempt to see how the different branches of stealthy communication research can inform each other. In this paper we take the first steps to remedying this deficiency. We identify open problems, point out gaps, and indicate directions for further research.