Achievable Rates for Two-Way Wire-Tap Channels

TL;DR

This paper investigates the achievable communication rates in two-way wire-tap channels, demonstrating that the inherent structure of two-way communication provides a natural encryption advantage against eavesdroppers.

Contribution

It introduces achievable rates for Gaussian and binary two-way wire-tap channels, highlighting their advantage over traditional multiple-access wire-tap channels.

Findings

Two-way channels offer a natural encryption mechanism.

Achievable rates are derived for Gaussian and binary models.

Two-way channels outperform one-way models in secure communication.

Abstract

We consider two-way wire-tap channels, where two users are communicating with each other in the presence of an eavesdropper, who has access to the communications through a multiple-access channel. We find achievable rates for two different scenarios, the Gaussian two-way wire-tap channel, (GTW-WT), and the binary additive two-way wire-tap channel, (BATW-WT). It is shown that the two-way channels inherently provide a unique advantage for wire-tapped scenarios, as the users know their own transmitted signals and in effect help encrypt the other user's messages, similar to a one-time pad. We compare the achievable rates to that of the Gaussian multiple-access wire-tap channel (GMAC-WT) to illustrate this advantage.