Strongly Secure Communications Over the Two-Way Wiretap Channel

TL;DR

This paper advances secure communication methods over the two-way wiretap channel by exploiting interference and cooperation, introducing new coding strategies that enhance secrecy and enable secret-key agreement, especially in Gaussian channels.

Contribution

It develops an improved achievable region using cooperative jamming and channel resolvability, offering novel strategies for strong secrecy in two-way wiretap channels.

Findings

Significant secrecy gains in Gaussian two-way wiretap channels.

Introduction of cooperative jamming as a source of common randomness.

Enhanced achievable regions compared to previous results.

Abstract

We consider the problem of secure communications over the two-way wiretap channel under a strong secrecy criterion. We improve existing results by developing an achievable region based on strategies that exploit both the interference at the eavesdropper's terminal and cooperation between legitimate users. We leverage the notion of channel resolvability for the multiple-access channel to analyze cooperative jamming and we show that the artificial noise created by cooperative jamming induces a source of common randomness that can be used for secret-key agreement. We illustrate the gain provided by this coding technique in the case of the Gaussian two-way wiretap channel, and we show significant improvements for some channel configurations.