Secret Communication with Feedback

TL;DR

This paper explores secure communication with feedback, proposing schemes that leverage feedback channels to generate shared secret keys and achieve higher secrecy rates in binary symmetric and Gaussian channels.

Contribution

It introduces a new achievability scheme utilizing feedback for secret key generation and combines it with existing coding schemes to improve secrecy rates.

Findings

Achieves improved secrecy rates in binary symmetric channels

Shows Schalkwijk-Kailath scheme attains secrecy capacity in Gaussian channels

Demonstrates feedback's effectiveness in secure communication

Abstract

Secure communication with feedback is studied. An achievability scheme in which the backward channel is used to generate a shared secret key is proposed. The scenario of binary symmetric forward and backward channels is considered, and a combination of the proposed scheme and Maurer's coding scheme is shown to achieve improved secrecy rates. The scenario of a Gaussian channel with perfect output feedback is also analyzed and the Schalkwijk-Kailath coding scheme is shown to achieve the secrecy capacity for this channel.