Request pattern change-based cache pollution attack detection and defense in edge computing

Through caching popular contents at the network edge, wireless edge caching can greatly reduce both the content request latency at mobile devices and the traffic burden at the core network. However, popularity-based caching strategies are vulnerable to Cache Pollution Attacks (CPAs) due to the weak security protection at both edge nodes and mobile devices. In CPAs, through initiating a large number of requests for unpopular contents, malicious users can pollute the edge caching space and degrade the caching efficiency. This paper firstly integrates the dynamic nature of content request and mobile devices into the edge caching framework, and introduces an eavesdroppingbased CPA strategy. Then, an edge caching mechanism, which contains a Request Pattern Change-based Cache Pollution Detection (RPC2PD) algorithm and an Attack-aware Cache Defense (ACD) algorithm, is proposed to defend against CPAs. Simulation results show that the proposed mechanism could effectively suppress the effects of CPAs on the caching performance and improve the cache hit ratio.