Security Aware Caching Placement Optimization Strategy in Cooperative Networks

Caching frequently requested contents at fog nodes has been proposed to alleviate the unprecedent pressure of limited backhaul capacity and decrease latency. However, due to the broadcast characteristic of wireless communication and limited resource, how to ensure information security is of vital importance. Compared with traditional encryption method, physical layer security has advantages on low computing complexity and resource consumption. In this paper, aiming at maximizing secrecy throughput, the Wynar’s encoding method is adopted to ensure communication security by jointly optimizing the caching placement strategy and secrecy rate. Numerical results have demonstrated that the proposed security aware caching placement strategy can outperform the other two baseline algorithms and achieve the tradeoff between diversity and security in cooperative networks.