云环境中基于信任分散策略的数据共享方案

Data sharing scheme based on trust decentralization in cloud environment

针对不完全可信云环境中数据共享的安全问题,提出基于信任分散策略的数据共享方案。将原始数据拆分成动态数据和静态数据,动态数据采用在用户私钥内添加全局标志的密文策略属性基加密算法加密存储于一个云端,并在用户撤销时利用代理重加密技术改变访问结构;静态数据采用对称加密算法加密,存储于另一云端。安全性分析和实验表明,该方案能有效防止动态数据的串谋攻击并保证用户撤销的后向安全性,满足实际云环境中数据安全共享需求。

According to the security problem of data sharing in the environment of incomplete credible cloud,this paper proposed a data sharing scheme based on the decentralization strategy of credit.This scheme divided the original data into dyna-mic and static data.The dynamic data’s encryption used ciphertext-policy attribute-based encryption algorithm that added the personal identification in the user’s private key,and then a cloud stored it.At the same time,this scheme used the proxy re-encryption technology to change the access structure when the user revoked.The static data’s encryption used a symmetric encryption algorithm,and another cloud stored it.The security analysis and experiments show that the proposed scheme can effectively prevent the collusion attack of dynamic data and guarantee the backward security of users,which can meet the requirement of data security sharing in the real cloud environment.