Secret Key Agreement Using Correlated Sources over the Generalized Multiple Access Channel

TL;DR

This paper investigates the limits of secret key agreement among three users with correlated sources and a generalized multiple access channel, deriving capacity regions and analyzing special cases including Gaussian channels.

Contribution

It introduces inner and outer bounds for the secret key capacity region in a complex multi-user setup with correlated sources and channels, including special case derivations.

Findings

Derived inner and outer bounds for the secret key capacity region.

Established the capacity region for a special Markov chain case.

Analyzed the Gaussian case within the proposed framework.

Abstract

A secret key agreement setup between three users is considered in which each of the users 1 and 2 intends to share a secret key with user 3 and users 1 and 2 are eavesdroppers with respect to each other. The three users observe i.i.d. outputs of correlated sources and there is a generalized discrete memoryless multiple access channel (GDMMAC) from users 1 and 2 to user 3 for communication between the users. The secret key agreement is established using the correlated sources and the GDMMAC. In this setup, inner and outer bounds of the secret key capacity region are investigated. Moreover, for a special case where the channel inputs and outputs and the sources form Markov chains in some order, the secret key capacity region is derived. Also a Gaussian case is considered in this setup.