文档介绍：中文摘要中又手两芰数字签名在公钥密码学中有着非常重要的地位。它在很多实际应用中提供认证性,数据完整性,不可否认性。相对于普通的数字签名,还有一些具有特殊应用的签名,比如盲签名与环签名,他们在一些特殊的领域起着很大的作用。无证书签名优势在于:1、签名验证者在验证签名时无需验证用户公钥的有效性。2、没有基于身份的密码系统中的密钥托管问题。由此可见,在无证书密码系统下设计签名方案是一件非常有意义的事。本文对一般签名、盲签名与环签名在无证书密码体制下的设计进行了研究。首先,本文中给出了一个无证书签名方案,这个方案基于双线性映射。此方案可以在无证书签名的最强安全模型下得到证明。在计算代价方面,这个方案签名和验证总共只需要2个pairing。这个方案比其它现有的能抵抗超级第1/II攻击者的方案都要高效。其次,我们首先给出了一个新的基于pairing的无证书签名方案,这个方案在某些情况下比先前方案都要高效。然后,基于这个签名力‘案,我们给出了一个无证书的盲签名方案。就我们所知,这是无证书体系下的第一个盲签名方案。最后,我们给出了一个无证书环签名方案;无证书环签名的安伞模型也被提出。这个环签名方案基于双线性映射。在签名阶段,这个方案只需计算2个pairing,而在验证阶段只需计算3个pairing,这个无证书环签名方案是第一个安全性能在我们的模型下得到证明的方案。关键词:无证书密码学;无证书签名;无证书盲签名;无证书环签名;计算Diffie—Hellmanl盲J题 Abst ract Digital signature is one ofthemostimportant primitives inpublic key cryptography. Itprovides authenticity,integrity and non-repudiation tomany kinds ofapplications. In addition toordinary signatures,there are some variants with specialapplications, such as blindsignatures andring signatures,they have the very major function in some special domains. Certificateless signatures mainly have twoadvantages: signature verifer. when verify the validity ofthesignatures,does not need toconfirm thevalidity of the users’public key eSCrOW problem which isinherent inIdentity- based public ,it isinteresting todesignsignature schemes in certificateless public key dissertation studiesordinary digital signature,blind signature,and ring signature incertificateless public key setting. Firstly,we present an efficient certificateless signature scheme using bilinear scheme can be proved secure inthe strongest security model of eel'- tificateless signature terms putational cost,totall:)|;only two pairing operations are required forsigning and ismore efficient than the other existing certificateless signature schemes secure against a super type I/II adversary. Secondly,we present another new -basedsignature scheme which hassome advantages o