高效撤销成员的密文策略属性基加密方案

Revocable Ciphertext-Policy Attribute-Based Encryption Scheme

针对密文策略属性基加密(CP-ABE)中成员撤销问题,该文将CP-ABE和子集不同方法相结合,提出一个可撤销成员的CP-ABE方案(R-CP-ABE),并将其合理布置在云储存平台上。该方案利用一次多项式将主密钥分解为两部分,并将其分别用于生成用户私钥和更新钥。此外,将时间属性嵌入用户更新钥和密文中,使得未撤销成员可以得到相应的更新钥,利用其私钥和更新钥可以获得一个正确的解密钥。与现有方案相比,该文方案不仅可以高效撤销成员,而且具有较短的更新钥和密文长度,特别适用于云存储平台,实现安全的细粒度访问控制的数据共享服务。

For the member revocation problem in ciphertext-based attribute based encryption(CP-ABE),this paper combines CP-ABE and subset different methods,proposes a revocable CP-ABE scheme(R-CP-ABE),and reasonably deploys it in cloud storage platform.our scheme uses a random polynomial of degree one to divide the master key into two parts-one for the user pri⁃vate key and the other for the update key.In addition,a time property is embedded into the user update key and the ciphertext si⁃multaneously,and the non-revoked users can get their update keys such that they can get their right decryption keys by their pri⁃vate keys and update keys.Compared with the existing schemes,our scheme not only can efficiently revoke users,but also has less group elements in the update key and the ciphertext.Our scheme is especially suitable for cloud storage platform,and implements the fine-grained access control for data sharing service securely.