基于区块链的细粒度云数据安全存储与删除方案

Secure Storage and Deletion Based on Blockchain for Cloud Data with Fine-grained Access Control

在基于云计算的存储与删除服务中,由于外包数据所有权和管理分离,现有的逻辑删除机制使云上的数据很容易暴露给未经授权的用户,甚至云服务器可能未遵循用户要求删除相应数据。为此,该文提出一种细粒度的安全云端数据存储与删除方案。基于椭圆曲线构造了基于密文策略的属性基加密以实现外包数据细粒度访问控制,应用区块链实现可公开验证的安全数据删除。该文方案具有责任可追踪性以及两方删除与可验证性等特性。理论分析与实验结果表明该文方案具有较好的安全性和较高的性能,能够满足云数据共享与安全删除的需求。

In the storage and deletion service provided by cloud computing,due to the separation of outsourced data ownership and management,the cloud server may not follow the user’s request to delete the corresponding data,and the outsourced data can be easily exposed to unauthorized users due to the widely-adopted logical deletion.Therefore,an efficient and secure cloud data storage and deletion scheme is proposed.Firstly,an attribute-based encryption based on ciphertext policy is constructed based on elliptic curves to achieve finegrained access control.Secondly,publicly verifiable data deletion is realized by using blockchain.The proposed scheme has the characteristics of responsibility traceability,two-party deletion and verifiability.Theoretical analysis and experimental results show that the presented scheme has more desirable security and performance,and can meet the needs of cloud data sharing and secure deletion.