Secure Multiplex Coding with Dependent and Non-Uniform Multiple Messages

TL;DR

This paper generalizes secure multiplex coding to handle dependent and non-uniform secret messages, providing practical, universal coding techniques for wire-tap and broadcast channels with confidentiality.

Contribution

It removes the independence and uniformity assumptions in SMC, introducing a channel resolvability-based approach and practical, universal coding constructions.

Findings

Generalized SMC for dependent, non-uniform messages

Provided practical coding methods using arbitrary error-correcting codes

Achieved universal coding for broadcast channels with confidential messages

Abstract

The secure multiplex coding (SMC) is a technique to remove rate loss in the coding for wire-tap channels and broadcast channels with confidential messages caused by the inclusion of random bits into transmitted signals. SMC replaces the random bits by other meaningful secret messages, and a collection of secret messages serves as the random bits to hide the rest of messages. In the previous researches, multiple secret messages were assumed to have independent and uniform distributions, which is difficult to be ensured in practice. We remove this restrictive assumption by a generalization of the channel resolvability technique. We also give practical construction techniques for SMC by using an arbitrary given error-correcting code as an ingredient, and channel-universal coding of SMC. By using the same principle as the channel-universal SMC, we give coding for the broadcast channel with confidential messages universal to both channel and source distributions.