Robust and Scalable Data Access Control in D2D Communications

As an emerging technique in 5G cellular networks, D2D communication efficiently utilizes the available resources. However, the concerns of data security, identity privacy, and system scalability have not been sufficiently addressed. In this paper, we propose a robust and scalable data access control scheme (RSDAC) in D2D communication, where the key build block is a multi-authority ciphertext-policy attribute-based encryption (MA-CP-ABE) with the large universe and verifiable outsourced decryption. In RSDAC, the system attribute universe is scalable, which is exponentially large without resource waste. Each base station (BS) governs the whole attribute universe individually. The data owner can define any monotonic access structure to encrypt its data. During the key generation phase, each BS can independently verify the user’s legitimacy and then generate an intermediate key for the legal user according to its attribute set. A core network server (CNS) acts as the central authority which will generate the final private key for the user basing on his intermediate key. We also design an efficient method to offload the complicated decryption to some devices with adequate computation resource and further check the correctness of decryption result. The security analysis and performance comparison indicate that our scheme is secure, efficient, and applicable.