一种改进的基于身份广播代理重加密云存储方案

存储安全是公共云应用诸多安全问题中最关键的问题之一，对云服务的快速发展有着重大影响。结合身份加密、代理重加密以及广播加密的特点，提出了一种新的云存储方案。该方案通过条件控制，实现了用户对远程密文数据代理重加密过程中的细粒度访问控制；基于身份加密，利用用户的身份属性作为公钥，减少了证书验证过程；结合广播的思想，以用户集合为单位进行加密，减少系统的计算消耗。实验表明，文章提出的方案可以实现密文数据云存储和共享，主要函数的时间开销合理，能够保证大规模用户接入时系统高效。

An improved identity-based broadcast proxy re-encryption storage scheme in cloud

The storage security is one of most important security problems in Public Cloud, it has become a significant reluctance in adopting Cloud. This paper proposed a new scheme for cloud storage which Based on the characteristics of identity encryption, proxy re-encryption and broadcast encryption. Through conditional control, the fine-grained access control in the process of proxy re encryption of remote encrypted data is achieved. Based on identity encryption, using the user''s identity as a public key to reduce the processing of certificate validation. Based on the idea of broadcast, encryption is carried out with the user set as a unit to reduce the consumption of the system. Experimental results show that the proposed scheme can achieve secure storage and sharing of encrypted data, the overhead of the main function is reasonable, and the system is efficient for large-scale user access.