Abstract: This paper proposes a forward-secure undeniable digital signature scheme based on zero-knowledge proof. By combining the undeniable digital signature with the forward-secure digital signature, the new scheme keeps the general property of undeniable digital signature, and has the character of forward-secure, namely, the loss can be reduced to the lowest once the secret key is lost (or stolen). The scheme has some features such as undeniable and unforgeable of the digital signature, and the size of key and signature are short. The idea of zero-knowledge proof is used in key update protocol, which guarantees key update is secure. The scheme is secure under the assumption of standard intractability problems.

Key words: Digital signature, Undeniable, Forward-secure, Zero-knowledge proof

摘要： 基于零知识的证明，提出了一种前向安全不可否认数字签名方案。将不可否认数字签名与前向安全数字签名结合起来，保持了不可否认数字签名的一般特点，并具有前向安全性，在签名密钥泄露的情况下可将损失减少到最小。该方案具有签名不可伪造性和不可否认性、签名和密钥长度短等特点。密钥更新协议使用了零知识证明的思想，保证密钥进化的安全性。在标准困难问题假设下，该方案是安 全的。

关键词: 数字签名, 不可否认, 前向安全, 零知识证明