An efficient fine‐grained searchable encryption for secure communication in IoT‐based vehicular social networks

Abstract Vehicle data security is a fundamental requirement in any vehicular social network (VSN). Encryption is the key technology to address this requirement. However, with encryption, we lose all the accessibility to the data. Further, we may need to provide differential access capabilities to the different users. The attribute‐based searchable encryption (ABSE) method satisfies all these requirements. It is a method for safely searching through encrypted files stored in a networked repository. It is a multi‐user encryption method that combines the advantages of attribute‐based encryption (ABE) with searchable encryption (SE). However, ABSE has an inherent cost and cannot be applied in a resource‐constrained setting. Therefore, the proposed scheme aims to reduce the computational cost by readily accommodating frequent changes in the access structure and using a secret key and search trapdoor of constant size. This, in turn, reduces the bandwidth requirement as well. In addition, the suggested technique requires constant pairing operations during the search phase, making the search operation fast. Quantitatively, the secret key and trapdoor storage costs have been reduced to two and four‐source group elements, respectively, and the number of bilinear pairing operations in the search algorithm has been reduced to four.