What is being done to mitigate the threat of kleptography?
There is a long line of research geared towards eliminating subliminal channels. By eliminating subliminal channels, the ability to carry out kleptographic attacks is greatly hampered. Gus Simmons introduced the idea of using a protocol involving randomization to destroy subliminal channels [Si84]. To destroy a particular subliminal channel that was identified, Simmons has the warden (in the prisoners’ problem) generate a random number x and modify the message that is sent from one prisoner to the other prisoner using x. This shows the dual nature of randomization; it can pave the way for subliminal communications, but at the same time it can be used in carefully crafted protocols to virtually eliminate the existence of subliminal channels. For other early results that use randomization to eliminate subliminal channels, see [Si85,DGB88]. See also [De88a,De88b,DGB88,HMP94,De96]. There are also concrete methods to protect against kleptographic attacks in particular. The nature of these s
