Wiretap Channel with Latent Variable Secrecy

The classic wiretap channel (WTC) problem is concerned with a transmitter (Alice) that wants to send a message W to the intended receiver (Bob) while keeping it secret from a passive eavesdropper (Eve). However, under certain communication scenarios, the user may not be interested in hiding the entire message from the eavesdropper, but rather in hiding its most sensitive attributes. While classic wiretap coding is capable of hiding these salient message attributes, it may be too stringent and better communication rates may be achievable. Motivated by the above, in this paper, we introduce and study the latent variable wiretap channel (LV-WTC) problem. Under this setting, the transmitter is interested in sending the message W to the intended receiver while keeping a correlated latent variable S (which models privacy sensitive attributes) secret from the eavesdropper. We present a message splitting based achievable scheme for the LV-WTC problem, which adapts to the structure of the conditional distribution PSW to achieve higher rates compared to the classical WTC. Several open problems and future directions that originate from this new communication problem are also discussed.