Secure Semantic Communication via Authenticated Searchable Proxy Re-Encryption in 6G Edge-Intelligent Networks

The emergence of sixth-generation (6G) edge-intelligent networks has shifted communication from bit-level transmission to semantic-level transmission, enabling context-aware and task-oriented connectivity among distributed devices. However, as semantic communication becomes increasingly integrated with distributed edge intelligence, protecting the confidentiality, privacy, and authenticity of semantic data in such networks remains a fundamental challenge. In this paper, we propose an authenticated certificateless searchable proxy re-encryption (AC-SPRE) scheme tailored for secure semantic communication in 6G edge environments. The proposed AC-SPRE allows edge servers to perform encrypted semantic task search and ciphertext re-encryption without accessing the underlying plaintext, while simultaneously verifying user authentication and preserving data privacy. Specifically, AC-SPRE enables authorized entities to search over encrypted semantic features, securely re-encrypt results for multiple users, and ensure semantic integrity in communication processes. Using certificateless cryptography, the scheme eliminates the certificate management and key escrow issues inherent in traditional public-key infrastructures. Security analysis proves that the proposed scheme achieves confidentiality, searchability, and authentication under the random oracle model, while experimental evaluation demonstrates its practicality and low computational overhead for edge-intelligent semantic applications.