Abstract: Device-to-Device (D2D) content sharing technology is faced with some serious security challenges,which can be adopted to make users more conveniently and efficiently obtain contents.For D2D content sharing scenarios with eavesdroppers,secure caching mechanism based on Maximum Distance Separable (MDS) coding was designed to improve caching performance and meet security requirement.Firstly,content provider selection scheme based on users’ distance and social trust was designed to avoid that the eavesdroppers were selected to cache contents,and select content providers who could obtain higher transmission performance.Based on this,social-related energy efficiency was proposed to ensure the transmission performance and make contents be cached in the content providers that users believed in by using social trust and energy efficiency.Further,content caching placement was designed by maximizing social-related energy efficiency,whose core advantage is that secrecy constraints based on MDS coding was proposed to achieve that eavesdroppers could not obtain enough encoded packets to recover original contents.Finally,social-aware D2D secure caching algorithm based on MDS coding was proposed.Simulation results show that compared with the D2D content secure caching algorithm that content providers are selected randomly,the optimal performance of the proposed algorithm is improved by 15%.Compared with the D2D content caching algorithm without secrecy constraints,the proposed algorithm needs to achieve information security with a performance loss of 42%,but it can achieve its optimal performance when the content provider’s cache capacity is lower.

Key words: Coded caching, Device-to-Device content sharing, Eavesdropping, Secure caching, Social trust