能保护隐私且属性可扩展的云数据共享

Cloud-based data sharing scheme with preserved privacy and supported attribute extension

提出一种具有隐私保护且属性可扩展的云数据共享方案。采用混合加密体制实现数据的机密性并保护用户的属性隐私,其中文件的加密采用标准的对称加密算法,对称密钥的加密采用密文策略下基于属性的加密算法。在匿名文件创建过程中,基于哈希函数对一个随机参数和文件进行绑定,实现系统的属性扩展。安全性分析表明,新方案具有语义安全性,可抵抗恶意用户和云服务器的合谋攻击,能在保护用户属性隐私的同时实现系统的属性扩展。

A cloud-based data sharing scheme with preserved privacy and supported attribute extension is proposed. In the proposed scheme, a hybrid encryption mechanism is adopted to realize data confidentiality and users＇ attribute privacy protection, where files are encrypted based on a standard symmetric encryption algorithm and symmetric keys are encrypted by a ciphertext-policy attribute-based encryption algorithm. In the phase of anonymous file creation, system attribute extension is achieved by binding a random parameter with a file based on hash functions. A security analysis indicates that the proposed has semantic security and is secure against collusion attacks from malicious users and cloud servers. In addition, it can simultaneously protect users＇ attribute privacy and support system attribute extension.