基于椭圆曲线密码体制的具有前向安全特性的签名方案

Signature Schemes with Forward Security Based on Elliptic Curve Cryptosystem

根据有限域上非超奇异椭圆曲线离散对数难解性假设,利用椭圆曲线上Weil配对的双线性性质设计了一种新的基于椭圆曲线密码体制的前向安全数字签名方案,并将前向安全特性和盲签名基本思想融为一体,在此方案的基础上又设计了一种前向安全强盲签名方案.与以往盲签名方案相比,这种前向安全强盲签名方案增加了前向安全特性,对盲签名的有效时间进行了控制,在保证签名前向安全的基础上进一步保护了消息发送方的隐私权,可应用于更加广泛的领域.本文还提出了时段因子的新概念,两种新方案均通过时段因子辅助私钥进化并将其作为签名的重要组成部分且参与验证过程,因此两种方案同时具备有效性、前向安全性和抗伪造性等性质,有效地确保了签名算法的安全性.

Based on the difficulty assumption in solving the non-supersingular elliptic curve discrete logarithm problem over finite field, this paper designs a new forward-secure signature scheme based on elliptic curve cryptosystem by using the bilinear property of Weil pairing defined on elliptic curves, and furthermore proposes a forward-secure strong blind signature scheme based on the proposed scheme by combining the fundamental ideas of forward security and blind signature. The proposed forward-secure strong blind signature scheme increases the forward security and limits the effective time of the blind signature compared with the previous blind signatures, by which the senders＇ privacy is further protected on the basis of ensuring forward-security, such that the proposed scheme has more extensive applications. By the introduction of a new conception named interval-factor assisting the secret key in evolving in this paper, the two proposed schemes have the features of correctness, forward-security and forging attack resistance, which ensures the safety throughout the lifetime of the schemes effectively. The interval-factor, as an important component of the signature, participates in the verification phase.