Secret Key Agreement by Soft-decision of Signals in Gaussian Maurer's Model

TL;DR

This paper proposes a soft-decision based protocol for secret key agreement in Gaussian Maurer's model, demonstrating higher key rates compared to hard-decision methods.

Contribution

The paper introduces a novel soft-decision protocol for secret key generation in Gaussian channels and derives a lower bound on its key rate.

Findings

Soft-decision protocol achieves higher key rates than hard-decision.

Lower bound on secret key rate is derived for the proposed protocol.

Soft-decision improves efficiency in Gaussian Maurer's model.

Abstract

We consider the problem of secret key agreement in Gaussian Maurer's Model. In Gaussian Maurer's model, legitimate receivers, Alice and Bob, and a wire-tapper, Eve, receive signals randomly generated by a satellite through three independent memoryless Gaussian channels respectively. Then Alice and Bob generate a common secret key from their received signals. In this model, we propose a protocol for generating a common secret key by using the result of soft-decision of Alice and Bob's received signals. Then, we calculate a lower bound on the secret key rate in our proposed protocol. As a result of comparison with the protocol that only uses hard-decision, we found that the higher rate is obtained by using our protocol.