Abstract: A proxy signature allows original signer to delegate his signing capability to the proxy signer in such a way that the proxy signer can sign messages on behalf of the original signer. This paper proposes a new probably secure signature scheme in the standard model. The security of new scheme is based on the intractability of q-strong Diffie-Hellman problem. The scheme is proved secure against existential forgery in adaptively chosen message attack in the standard model. Compared with existing schemes, the proposed scheme which needs less public parameters with a tight security reduction has obvious advantages in generating secret key, standard signing, proxy signing and generating delegation, etc.

Key words: proxy signature, standard model, q-strong Diffie-Hellman problem

摘要： 代理签名方案允许原始签名者将自己的签名权力授权给代理签名者, 使得代理签名者能够代表原始签名者对消息进行签名。提出了一个新的标准模型下可证安全的代理签名方案, 其安全性基于q-强 Diffie-Hellman困难问题, 证明了该方案在标准模型下能够抵抗适应性选择消息攻击下的存在性伪造。与已有的方案进行比较, 提出的方案需要较少的公共参数, 实现了紧凑的安全归约, 并且在密钥生成、标准签名、授权生成、代理签名生成等阶段具有较高的效率。

关键词: 代理签名, 标准模型, q-强Diffie-Hellman问题