The Wiretap Channel with Generalized Feedback: Secure Communication and Key Generation

TL;DR

This paper introduces a new scheme for the wiretap channel with generalized feedback that enhances secure communication by generating shared secret keys, leading to new capacity results and unifying existing approaches.

Contribution

It presents a novel achievable scheme that uses feedback to generate secret keys, providing new capacity results and unifying previous methods in secure communication.

Findings

New capacity results for specific channels

Scheme recovers and generalizes previous rate regions

Provides insights into secret key agreement

Abstract

It is a well-known fact that feedback does not increase the capacity of point-to-point memoryless channels, however, its effect in secure communications is not fully understood yet. In this work, an achievable scheme for the wiretap channel with generalized feedback is presented. This scheme, which uses the feedback signal to generate a shared secret key between the legitimate users, encrypts the message to be sent at the bit level. New capacity results for a class of channels are provided, as well as some new insights into the secret key agreement problem. Moreover, this scheme recovers previously reported rate regions from the literature, and thus it can be seen as a generalization that unifies several results in the field.