关键词: 格, 属性基加密, 属性撤销

Abstract:

Attribute-based encryption mechanism is widely used in outsourcing environment because of its charac-teristics of “one-to-many” communication. However, users?? attributes often change dynamically. In order to solve the problem of attribute revocation in the attribute-based encryption scheme in the outsourcing systems, combined with the attribute-based encryption scheme proposed by Yan et al., a revocable ciphertext-policy attribute-based encryption in data outsourcing systems from lattices is introduced. The scheme uses the LWE (learning with error) problem to construct the encryption and decryption algorithm, which can resist the quantum attack. Tree-access structure is adopted to realize flexible fine-grained access strategy. In addition, with the help of the data outsourcing management server, the attribute key and ciphertext are updated to achieve immediate attribute revocation. The scheme is proven to satisfy the security under the selective attribute and selective plaintext attack. The comparative analysis shows that the scheme has a significant improvement in performance, and supports immediate attribute revocation, which is more suitable for the dynamic change of users in the outsourcing systems, such as social network platform.

Key words: lattices, attribute-based encryption, attribute revocation