An authorized equality test on identity‐based cryptosystem for mobile social networking applications

Abstract

AbstractThe widespread adoption of social network applications and smart mobile devices has yielded a massive amount of data transmitted through the networks. Fortunately, social network service providers offer a wide range of storage capacity and data management functionality. Accordingly, the data can be uploaded to the social servers for processing and then accessible elsewhere. Nevertheless, considering the untrusted nature of the social servers, it becomes crucial to protect the data before uploading it to the server. Unfortunately, encryption incurs another severe problem in providing search functionality on encrypted data stored on the server. In addition, most of the existing solutions are inefficient to deploy on mobile devices due to the limited resources and computing capabilities. To address this issue, we propose an authorized equality test on identity‐based cryptosystem (AET‐IBC) scheme in this article. The scheme allows the server to test if two different ciphertexts encapsulate the same message. Besides, it supports different authorization methods to enhance the privacy. Furthermore, based on the random oracle model, we prove the security of the proposed scheme to be equivalent to the modified bilinear Diffie‐Hellman intractable assumption. Finally, the efficiency analysis shows that the AET‐IBC scheme is practicable and convenient for mobile social networking applications.