Secure Communication via Modulation Order Confusion

TL;DR

This paper introduces a novel secure communication method that confuses modulation order to prevent eavesdropping, employing different schemes for single-antenna, multi-antenna, and RIS-assisted systems, effectively thwarting classifiers.

Contribution

It presents new modulation order confusion schemes for various wireless systems, enhancing security without sacrificing communication quality.

Findings

Effectively defeats deep-learning and expert classifiers.

Maintains communication performance while confusing modulation.

Extends to RIS-assisted systems with joint beamforming.

Abstract

With the increasing threat posed by modulation classification to wireless security, this paper proposes a secure communication framework based on modulation order confusion (MOC), which intentionally disguises the original modulation as a higher- or lower-order one to mislead eavesdroppers. For single-antenna systems, two schemes are developed: symbol random mapping and symbol time diversity, enabling modulation order confusion with customized receivers. For multi-antenna systems, receiver-transparent MOC schemes are proposed, including series-expansion-based and constellation-path-based signal designs, and are further extended to RIS-assisted systems with joint beamformer and RIS reflection design. Numerical results show that the proposed schemes effectively defeat both deep-learning-based and expert-knowledge-based modulation classifiers without degrading communication performance.