Secure Lossy Source-Channel Wiretapping with Side Information at the Receiving Terminals

TL;DR

This paper investigates secure lossy source-channel communication with side information at receivers, deriving bounds on the rate-distortion-equivocation region and demonstrating how statistical differences can enhance secrecy.

Contribution

It generalizes secure source coding and wiretap channel problems by deriving bounds for arbitrary channels and side information, and shows separation holds in some cases.

Findings

Derived inner and outer bounds on the rate-distortion-equivocation region.

Showed that separation holds in certain special cases.

Demonstrated that statistical differences can be exploited for enhanced secrecy.

Abstract

The problem of secure lossy source-channel wiretapping with arbitrarily correlated side informations at both receivers is investigated. This scenario consists of an encoder (referred to as Alice) that wishes to compress a source and send it through a noisy channel to a legitimate receiver (referred to as Bob). In this context, Alice must simultaneously satisfy the desired requirements on the distortion level at Bob, and the equivocation rate at the eavesdropper (referred to as Eve). This setting can be seen as a generalization of the conventional problems of secure source coding with side information at the decoders, and the wiretap channel. Inner and outer bounds on the rate-distortion-equivocation region for the case of arbitrary channels and side informations are derived. In some special cases of interest, it is shown that separation holds. By means of an appropriate coding, the presence of any statistical difference among the side informations, the channel noises, and the distortion at Bob can be fully exploited in terms of secrecy.