Revocable and anonymous searchable encryption in multi-user setting

摘要

With powerful storage and computing capacities provided by cloud server provider(CSP), cloud customers can relieve from heavy storage and maintenance burden in cloud computing. Therefore, searchable encryption(SE) technology becomes a fundamental solution to search over encrypted data in outsourcing service. However, the genuine safety of SE schemes should concentrate not only on keyword privacy but also on user privacy as information tracking may leak user identity. For example, in the personal health record system, the malicious CSP may match sensitive disease information(cancer or AIDS) with certain patient. In addition, practical SE scheme should not be confined to single-user setting because of its limitations. While SE schemes applied to multi-user setting may result in additional secret key and ciphertext updating burden due to frequent user revocation. Along this direction, we define a revocable and anonymous SE scheme in multiple-user setting, which is scalable and efficient in user revocation and anonymity. Security analysis shows that our scheme is Anonymous-Revocable-ID-CPA secure under Decision Bilinear Diffie–Hellman assumption and is able to effectively resist decryption key exposure threat. Copyright © 2015 John Wiley & Sons, Ltd.