Reliable Deniable Communication: Hiding Messages in Noise
Alice is in jail, and may wish to communicate reliably with Bob in the neighboring cell, over n uses of a noisy BSC (if she stays silent, the input to the channel is all zeroes). Unfortunately, the warden Willie is monitoring Alice (though his observations are significantly noisier, since his CCTV camera is low-quality). Willie only wishes to detect Alice's "Transmission status" (i.e., he only wants to know whether she's talking or not, and doesn't necessarily care what she's saying). A transmitter Alice may wish to reliably transmit a message to a receiver Bob over a Binary Symmetric Channel (BSC), while simultaneously ensuring that her transmission is deniable from an eavesdropper Willie.