支持大属性集且计算可外包的属性基签名方案

An Attribute-based Signature Scheme Supporting Large Universe and Computing Outsourcing

在移动医疗场景中,利用属性基签名技术可以保证电子医疗数据的安全共享。然而,普通的属性基签名方案仅支持小属性集,在系统初始化阶段需要预先设定属性集空间的大小,这导致系统运行变得复杂。此外,现有支持大属性集的属性基签名方案在签名阶段又存在大量的计算开销。针对以上不足,提出了一种支持大属性集且计算可外包的属性基签名方案。首先,该方案支持大属性集,有效避免了预先设定属性集空间大小的缺陷。其次,该方案将签名过程中的大量计算进行外包,并且对外包签名提供了检测机制,避免了云服务器对部分签名的伪造。另外,该方案采用区块链与云服务器结合的链上链下存储方式对电子医疗数据进行存储,极大地便利了电子医疗数据的安全存储与共享。安全性分析和实验结果表明,该方案在保证外包签名安全性的前提下提高了系统的效率。

In mobile health scenario, attribute-based signature technologies could ensure the security of electronic medical data sharing. However, common attribute-based signature schemes only support small universe, and the size of attribute set space needs to be preset in the system initialization phase, which leads to complicated system operation. In addition, existing attribute-based signature schemes supporting large universe have a large amount of computing overhead in the signature phase. To solve these problems, an attribute-based signature scheme supporting a large universe and computing outsourcing is proposed. Firstly, the scheme supports large universe and avoids the shortcoming of presetting the attribute set space size. Then, the scheme outsources plenty of computation in the signing process, and provides a detection mechanism for outsourcing signature, avoiding forgery of partial signature by the cloud server. Moreover, the scheme adopts the on-chain off-chain storage mode by combining the blockchains and the cloud server to store electronic medical data, which greatly facilitates the secure storage and sharing of electronic medical data. Security analysis and experimental results show that the proposed scheme improves the efficiency of the system while ensuring the security of the outsourcing signature.