椭圆曲线上代理盲签名方案的改进

Improvement of Proxy Blind Signature Scheme on Elliptic Curve

摘要: 通过对Tan等人提出的基于椭圆曲线上的离散对数问题(ECDLP)的代理盲签名方案分析，指出该方案具有不安全性，不能抵抗四种常见的伪造攻击：原始签名者和签名接收者的伪造、一般性攻击及签名接收者的一般伪造攻击，且不满足不可链接性。为了克服上述不足之处，提出了一种改进的方案，在代理授权阶段引入委托证书改进代理签名私钥，同时去掉签名生成阶段的参数，使得可以抵抗原始签名者和接收者的伪造攻击，其安全性等价于解离散对数难题，同时方案也具有不可链接性。同时在签名阶段引入签名请求者的私钥，代理签名人无法将盲消息的签名和消息签名联系起来，即签名是不可追踪的。

Abstract: Through the analysis of the proxy blind signature scheme based on the discrete logarithm problem on elliptic curve (ECDLP) proposed by Tan et al., it is pointed out that the scheme is insecure and cannot resist four common forgery attacks: forgery of the original signer and signature receiver, general attack and general forgery attack of the signature receiver, and does not meet the requirements of unlinkability. In order to overcome the above shortcomings, an improved scheme is proposed. In the proxy authorization phase, a delegation certificate is introduced to improve the proxy signature private key, and the parameters in the signature generation phase are removed, so that it can resist the forgery attacks of the original signer and receiver. Its security is equivalent to solving the discrete logarithm problem, and the scheme is also non linkable. At the same time, the private key of the signature requester is introduced in the signature phase, so the proxy signer cannot as-sociate the blind message signature with the message signature, that is, the signature is untraceable.