Secure Semantic Transmission via Semantic Obfuscation and Physical-Layer Keying

Abstract

The adoption of semantic communication in wireless systems introduces security challenges, as latent semantic features may leak sensitive information when intercepted. This paper proposes a secure semantic transmission framework based on semantic obfuscation and physical-layer keying. At the transmitter, semantic obfuscation conceals sensitive information in latent representations while preserving reconstructability. A shared secret key is dynamically generated from wireless channel reciprocity, enabling lightweight physical-layer security without centralized key distribution. The obfuscated features are further protected via a key-driven protection process before transmission. At the receiver, the semantic decoder reconstructs the original content from the secured representations. Simulation results demonstrate that the proposed scheme effectively prevents unauthorized reconstruction while maintaining reliable semantic transmission performance.