Chirp-Permuted AFDM for Quantum-Resilient Physical-Layer Secure Communications

TL;DR

This paper introduces a secure physical-layer communication scheme using a chirp-permuted AFDM waveform, providing quantum-resilient security by making eavesdropper detection computationally infeasible.

Contribution

The paper proposes a novel chirp-permuted AFDM waveform for 6G security, demonstrating its robustness against classical and quantum attacks.

Findings

Permutation complexity is factorially scalable, making brute-force attacks infeasible.

Probability of security breach via random guessing is negligible.

Scheme ensures secure communication even with perfect channel knowledge.

Abstract

We present a novel physical-layer secure communications scheme based on a chirp-permuted variant of the affine frequency division multiplexing (AFDM) waveform recently proposed for sixth-generation (6G) systems, which ensures that eavesdroppers unaware of the correct chirp-permutation face significant challenges in signal detection, even with perfect channel state information (CSI) and co-location with the legitimate user. The security of the proposed scheme is studied in terms of the complexity required to find the correct permutation via classical and quantum search algorithms, analytically shown to be infeasible in both cases due to the factorially-scaling search space, and the probability of breach under the random-guess approach, also shown to be negligible.