Chang Yan, Zhang Shi-Bin, Yan Li-Li, Wan Guo-Gen
School of Cybersecurity, Chengdu University of Information Technology, Chengdu, 610225, China.
Sci Rep. 2020 Jun 3;10(1):9074. doi: 10.1038/s41598-020-65738-y.
A quantum scheme for cloud data sharing based on proxy re-encryption is proposed. The user Alice stores the cipher-text of her data on cloud data center. When Alice wants to share her data with another user Bob, Alice is called the delegator and Bob is called the delegatee. The cloud service provider (called the proxy) can convert the delegator's cipher-text into the delegatee's cipher-text without decrypting the former, so that the delegatee can get the plain-text of Alice's data with his private key. The proxy cannot obtain the plain-text of the user's data stored on cloud data center. Delegator in the protocol should have the ability of producing Bell states, performing Bell basis and Z-basis measurements, and storing qubits. The quantum requirements for the delegatee are reduced. The delegatee needs to have the ability of reflecting and performing Z-basis measurement. One secret at a time (one-time one-pad) is theoretically implemented, especially when the same data is shared multiple times. The anti-selection plain-text attack security and the anti-selective cipher-text attack security are realized. Fine-granularity secret data sharing is achieved flexibly.
提出了一种基于代理重加密的云数据共享量子方案。用户爱丽丝将其数据的密文存储在云数据中心。当爱丽丝想要与另一个用户鲍勃共享她的数据时，爱丽丝被称为委托方，鲍勃被称为受托方。云服务提供商（称为代理）可以在不解密委托方密文的情况下将其转换为受托方的密文，以便受托方可以使用其私钥获取爱丽丝数据的明文。代理无法获取存储在云数据中心的用户数据的明文。协议中的委托方应具备产生贝尔态、执行贝尔基和Z基测量以及存储量子比特的能力。对受托方的量子要求降低了。受托方需要具备反射和执行Z基测量的能力。理论上实现了一次一密，特别是当相同数据被多次共享时。实现了抗选择明文攻击安全性和抗选择密文攻击安全性。灵活地实现了细粒度秘密数据共享。
