Physical Layer Security for Edge Caching in 6G Networks

The sixth generation (6G) of wireless cellular networks is envisioned to provide connected intelligence for mobile devices through ambient computing and caching services. Edge caching is an efficient solution to reduce transmission delay and offload traffic from backhaul network by caching frequently requested content on the edge servers. However, the security problems of edge caching such as eavesdropping are seldom considered in the literature. In this paper, we propose a two-hop edge caching scheme where physical layer security (PLS) and probabilistic caching scheme are adopted to prevent data from being eavesdropped. We jointly optimize content caching probability and redundancy rate to maximize the secure transmission probability. Extensive simulation results show that the proposed scheme can significantly improve the secure transmission probability of edge cache network facing the threat of eavesdropping.