Data-Driven Dynamic Interleaving for Secure Communication in RSMA Networks

This letter introduces a novel data-dependent interleaving technique to enhance the security of rate-splitting multiple access (RSMA) networks by protecting the common stream against eavesdropping threats. Specifically, the proposed method leverages the RSMA structure by interleaving the common bits of each user based on a sequence derived from their private bits. By decoding its private stream, the legitimate receiver reconstructs the interleaving sequence established by the transmitter, enabling successful de-interleaving of the common stream. Conversely, an eavesdropper (Eve), unable to deduce the dynamically changing interleaving permutations, is left with minimal information. A private bit selection strategy is introduced to complement this mechanism to achieve two key objectives: minimizing reconstruction distortion for the legitimate receiver and maximizing equivocation for Eve. Simulation results validate the effectiveness of the proposed approach, demonstrating substantial security gains while maintaining robust system performance.