Revocable and Unbounded Attribute-Based Encryption Scheme with Adaptive Security for Integrating Digital Twins in Internet of Things

Internet of Things (IoTs) has been a burgeoning field that transforms the ubiquitous objects to interconnected devices and intelligent system. Today, with the emerging of innovative technologies such as cloud computing, the IoT sector is in a race to leverage these novel technologies to achieve optimal performance. Naturally the Digital Twins (DTs) architecture acts as an indispensable intermediary bridge to couple the IoT domain with these lastest technologies together. However, a tremendous obstacle is that the current Revocable Attribute-Based Encryption (RABE) schemes applied in the DTs paradigm fail to balance the efficiency, security and scalability simultaneously. In this paper, we tackle this challenge by presenting an unbounded and efficient direct RABE scheme with adaptive security. Compared with the previous schemes in this domain, our approach achieves revocable and fine-grained access control efficiently by employing the arithmetic span program (ASP) as the access structure. In this way, the expensive bilinear pairing and exponentiation operations are reduced significantly. Moreover, the unbounded property is satisfied in our scheme since the parameters are not required to be predefined in the setup phase. At last, with the support of the Matrix Decisional Diffie-Hellman (MDDH) assumption, the proposed scheme is proved to achieve adaptive security by adopting dual system encryption methodology. Theoretical comparison and implementation results demonstrate our proposed scheme possesses prominent practicability, scalability and efficiency.