支持临时解密授权的密文策略属性加密方案

Ciphertext-policy attribute-based encryption scheme supporting temporary decryption authorization

属性加密是在云环境下实现细粒度访问控制的有效工具,但同类方案并未较好地解决数据所有者的隐私保护和解密权限临时授权问题。文章将属性代理重加密技术与Nishide等的属性加密方案相结合,提出同时支持访问策略隐藏和解密权限临时授权的密文策略属性加密方案。此外,文章利用新方案解决了医疗云环境下属性访问控制系统的构造问题。安全性分析表明,新的属性加密方案并未破坏底层方案的安全性,而且不会向代理服务器泄露数据所有者的解密私钥。

Attribute-based encryption(ABE)is an effective tool for fine-grained access control in cloud environments.Nevertheless,existing schemes do not address the problems of users’privacy protection and temporary decryption authorization well.By incorporating the technique of attribute-based proxy re-encryption with Nishide et al.’s ABE,the paper proposes a ciphertext-policy ABE that supports both access policy hiding and temporary decryption authorization.Additionally,the new scheme can help to construct an attribute-based access control system oriented to a healthcare cloud environment.Security analysis shows that the new scheme does not compromise the security of the underlying scheme and does not disclose the data owner’s decryption key to proxy servers.