针对Paterson-Schuldt标准模型下可证安全的身份基签名方案中安全归约的不紧密性,利用双线性对性质,提出一个身份基签名方案.该方案使用Waters和Gentry身份基加密方案中密钥生成算法的思想,能回答所有私钥询问和签名询问,从而保证了紧密的安全归约和弱安全假设,同时在标准模型下可证安全.安全性分析结果表明,基于改进计算性Diffie-Hellman假设所提方案能抵抗适应性选择消息攻击下的存在性伪造. Aiming at the inaccuracy of security reduction in the provable security signature scheme under the Paterson-Schuldt standard model, an identity-based signature scheme based on the bilinear pairing scheme is proposed. This scheme uses Waters and Gentry identity-based encryption schemes Key generation algorithm can answer all private key queries and signature queries, thus ensuring a tight security reduction and weak security assumptions, while under the standard model can be certified security.Security analysis results show that based on improved computational Diffie- Hellman assumes that the proposed scheme can resist the existence counterfeiting under the attack of adaptive choice message.