【摘要】 属性撤销是属性基加密方案在实际应用中亟须解决的问题,已有支持间接撤销模式的可撤销属性基加密方案存在撤销延时或需要更新密钥及密文等问题。为此,提出一种间接模式下基于代理的支持属性即时撤销的密钥策略属性基加密方案,该方案不需要用户更新密钥及重加密密文,通过在解密过程中引入代理实现撤销管理,减轻了授权机构的工作量,其要求代理为半可信,不支持为撤销用户提供访问权限及解密密文。分析结果表明,该方案支持细粒度访问控制策略,并且可以实现系统属性的撤销、用户的撤销及用户的部分属性撤销。更多还原

【Abstract】 Attribute revocation is crucial to the practical use of Attribute-based Encryption(ABE). Most of the existing revocable ABE schemes under the indirect revocation model suffer in terms of delaying in revocation or updating keys and ciphertexts. To address this,this paper proposes a proxy-based immediate attribute revocation Key Policy(KP)attribute-based encryption under the indirect model without issuing new keys or re-encrypting existing ciphertexts. It achieves attribute revocation by introducing a proxy in the decryption process and reduces the burden for the key authority. The proxy is semi-trusted which revokes user access privileges and cannot decrypt ciphertexts. Analysis results show that the scheme supports fine-grained access control policies and achieves three kinds of revocation including system attribute revocation,user revocation and user attribute revocation.更多还原