A Channel Model of Transceivers for Multiterminal Secret Key Agreement

TL;DR

This paper introduces a novel channel model for transceivers in multiterminal secret key agreement, providing bounds and capacity results under specific conditions, advancing understanding of secret key generation with correlated channels.

Contribution

It proposes a new transceiver channel model where terminals control inputs and observe outputs simultaneously, and derives capacity bounds and exact capacity under certain assumptions.

Findings

Established upper and lower bounds for secret key capacity.

Proved capacity under noninteractive public communication and independent inputs.

Enhanced the theoretical framework for secret key agreement over noisy channels.

Abstract

Information theoretic secret key agreement is impossible without making initial assumptions. One type of initial assumption is correlated random variables that are generated by using a noisy channel that connects the terminals. Terminals use the correlated random variables and communication over a reliable public channel to arrive at a shared secret key. Previous channel models assume that each terminal either controls one input to the channel, or receives one output variable of the channel. In this paper, we propose a new channel model of transceivers where each terminal simultaneously controls an input variable and observes an output variable of the (noisy) channel. We give upper and lower bounds for the secret key capacity (i.e., highest achievable key rate) of this transceiver model, and prove the secret key capacity under the conditions that the public communication is noninteractive and input variables of the noisy channel are independent.