Secret Key Agreement from Vector Gaussian Sources by Rate Limited Public Communication

TL;DR

This paper characterizes the optimal trade-off between secret key rate and public communication rate for Gaussian sources using a Gaussian optimization framework, employing the enhancement technique from MIMO channels.

Contribution

It provides a new Gaussian optimization-based characterization of secret key agreement with one-way public communication for vector Gaussian sources.

Findings

Optimal trade-off characterized as a Gaussian optimization problem

Utilizes enhancement technique from MIMO Gaussian broadcast channels

Advances understanding of secret key agreement limits in Gaussian settings

Abstract

We investigate the secret key agreement from correlated vector Gaussian sources in which the legitimate parties can use the public communication with limited rate. For the class of protocols with the one-way public communication, we show that the optimal trade-off between the rate of key generation and the rate of the public communication is characterized as an optimization problem of a Gaussian random variable. The characterization is derived by using the enhancement technique introduced by Weingarten et.al. for MIMO Gaussian broadcast channel.