摘要： 为降低属性基加密(ABE)方案的计算费用,提出一个可撤销用户的外包加解密密文-策略ABE(CP-ABE)方案。将加解密过程中复杂的计算转移到云服务器中,从而降低用户的加解密计算量。利用中国剩余定理实现用户撤销和密文更新,而未被撤销用户则无需进行密钥更新。分析结果表明,与Zhou等人的方案相比,CP-ABE方案的计算性能约有28%的提升,并在一般群模型下可证明安全。

关键词: 属性基加密, 密文访问控制, 外包加解密计算, 用户撤销, 密钥更新, 中国剩余定理

Abstract: In order to reduce the computational costs of Attribute-based Encryption(ABE) scheme,this paper proposes an outsourced encryption and decryption Ciphertext-policy ABE(CP-ABE) scheme with user revocation.It delegates the complex computation of the encryption and decryption process to the cloud server to reduce the user’s encryption and decryption computational cost.Moreover,the proposed scheme implements user revocation and ciphertext update by using the Chinese remainder theorem,and makes the unrevoked users do not need to update their decrypted key.Analysis results show that,compared with the scheme proposed by Zhou et al.,the proposed scheme can improve computational performance,and it can be proved secure under general group model.

Key words: Attribute-based Encryption(ABE), ciphertext access control, outsourced encryption and decryption computation, user revocation, key update, Chinese remainder theorem

中图分类号: 

• TP309