移动互联网环境下轻量级SM2两方协同签名

Efficient Two-Party SM2 Signing Protocol for Mobile Internet

近年来无线通信技术的发展极大促进了移动设备的普及,用户可以使用移动设备随时随地访问到网络服务.由于网络空间的虚拟性,数字签名作为一种具有消息完整性认证、可鉴别性和不可否认性的技术应运而生.但是,移动设备自身存在易丢失或被劫持等安全隐患,导致对签名密钥(数字签名的信任根)的保护相对较弱.为了保护密钥安全,国内外学者提出了两方协同签名,防止密钥存储或使用过程中存在欺诈或盗用等恶意行为.针对GM T 0003—2012《SM2椭圆曲线公钥密码术》标准中的SM2数字签名算法,考虑客户端服务器这种非平衡构架,设计一种轻量级的SM2两方协同签名协议是具有理论和应用价值的.具体来讲,客户端和服务器以交互的方式产生有效签名,同时保证此过程中没有恢复完整的签名密钥.所提协议的性能也可通过实验测试的结果得到佐证,即客户端生成单个签名操作需4.381 ms,大致相当于遵循原始SM2签名算法所需的耗时,可见SM2两方协同签名具有很强的实用性.

Rapid development of wireless communication technology has greatly promoted the ubiquitousness of mobile devices.Mobile devices enable users to access Internet services anytime and anywhere.Because of the conjecture of the cyberspace,the digital signature is used as a kind of technique with the functionality of the integrity authentication,identification,and non-repudiation.However,mobile devices tend to be more easily lost or hijacked cause relatively weak protection on the private keys(the root of the digital signature s trust).To ensure the confidentiality of private keys,two-party signature is a viable method to avoid fraudulent key usage or key theft.Therefore,in this paper,we focus on the SM2 signature algorithm,which is standardized in GM T 0003—2012“SM2 Elliptic Curve Public Key Cryptography”,and design a lightweight two-party SM2 signing protocol.Unlike standard secret sharing,a valid signature now is generated interactively between a client and a server,while the original key never being exposed.We mathematically prove the security of the proposed protocol.Findings from the performance evaluation of the protocol show that it achieves good performance,with a single signing operation taking 4.381 ms for the client and being roughly equal to the original SM2 signature in the same testing environment.