An access control scheme with dynamic user management and cloud-aided decryption

Abstract

Ciphertext-policy attribute-based encryption is becoming a cryptographic solution to realize fine-grained access control. However, some important problems have not been effectively solved yet such as (i) low efficiency of dynamic change of a user or his attribute and (ii) high computation cost at user end. In this paper, we propose an access control scheme with dynamic user management using a version key and especially realize direct cloud-aided attribute revocation without updating another user's key or re-encrypting ciphertexts. We present a cloud-aided decryption method with which most of decrypting work can be transferred to cloud. Compared with the existing schemes, our scheme causes less computation cost at user end and supports efficient dynamic change of a user or his attribute. Simulation indicates that our direct cloud-aided attribute revocation method takes less time. Copyright © 2017 John Wiley & Sons, Ltd.