关键词: 属性基加密, 访问控制策略, 分权密文策略, 多授权机构

Abstract:

Attribute-based encryption (ABE) scheme takes attributes as the public key and associates the ciphertext and user’s secret key with attributes, so it can express flexibly access control policies. This scheme dramatically reduces the network bandwidth and the cost of sending nodes’ operations in fine-grained access control of data sharing. As a generalization of a single authority ABE scheme, multi-authority ABE scheme reduces the burden of single authority and the security risk, while meeting the needs of distributed applications more easy. To address the issue that the attributes cannot be reused in multi-authority ABE scheme, this paper proposes an improved multi-authority ABE scheme called DCP-ABE scheme, which introduces the global identifier of authority. In the encryption stage, by binding the ciphertext components related to the attribute with the global identifier of authority that manages this attribute, the attributes managed by different authorities can be reused, which expands the practicality of the scheme. In addition, in this scheme, any authority can dynamically join or leave the encryption system, which no longer needs the management of the central authority.

Key words: attribute-based encryption, access control policy, decentralized ciphertext policy, multi-authority