An identity based universal designated verifier signature scheme secure in the standard model

Universal designated verifier signature was first introduced by Steinfeld, Bull, Wang and Pieprzyk in Asiacrypt 2003. In the universal designated verifier signature scheme, any holder of a signature can designate the signature to any desired designated verifier, such that only the designated verifier will believe that the signature holder holds a valid signature. In SecUbiq’05 [Zhang Fangguo, Susilo Willy, Mu Yi, Chen Xiaofeng, 2005. Identity-based universal designated verifier signatures. In: The First International Workshop on Security in Ubiquitous Computing Systems, Nagasaki, Japan, LNCS 3823. Springer-Verlag, Berlin, pp. 825-834] first extended this notion to the identity based setting and proposed two identity based universal designated verifier signature schemes. However, the security of their scheme is based on the random oracle model. Up to now, there is no provably secure identity based universal designated verifier signature scheme in the standard model. In this paper, we propose the first identity based universal designated verifier signature scheme whose security can be proven in the standard model based on the hardness of the computational Diffie-Hellman (CDH) problem.     

一种基于双线性对的强指定验证者签名方案

强指定验证者签名能够解决不向第3方证明发送方身份的前提下,仅指定的接收方可验证消息发送方身份的问题。基于计算双线性Diffe-Hellman假定,利用双线性对,提出了一种强指定验证者签名方案。该方案具有不可伪造性、签名者身份的隐私性和不可传递性。在团购、政府招标、艺术品拍卖等典型电子商务应用中具有现实意义。     

基于身份的强指定验证者签名方案

针对近期提出的基于身份强指定验证者签名方案的安全漏洞,通过采用在随机Oracle模式安全的知识的零知识证明方法,构建一个安全的基于身份的强指定验证者签名方案.同时与以往体制相比,实现效率有明显提高.     

限制多方验证者签名的方案

提出了限制多方验证者签名的精确定义，构造了一个有效的限制多方验证者签名方案，该方案只计算一次签名就能同时限制多个验证者验证签名，弥补了一般限制验证者签名方案只有一个限制验证者的局限。分析了在BDHP困难性假设下达到期望的安全需求。该方案不仅支持否认协议，而且比一般限制单方验证者签名方案执行多次的效率高。     

TMN密码协议的SMV分析

MV是分析有限状态系统的一种工具,三方密码协议运行模式分析法是分析密码协议的有效方法之一,为了说明这种方法的可行性,使用三方密码协议运行模式分析法,并借助状态探测工具SMV分析了TMN密码协议,并成功地找到了对TMN协议的19种攻击。     

对一个数字签名方案安全性证明的注记

研究了Willy,Zhang和Yi等学者提出的基于身份的强指定验证者签名方案（简记为WZY方案）的安全性证明,发现在他们的安全性证明中存在漏洞：在证明签名方案的不可伪造性时,敌手拥有指定验证者的私钥。在一个简单的假设下：假设对于一个有效的输入,Hash函数的输出是随机的,并且敌手事先知道这个输入,重新证明了WZY方案的不可伪造性依赖于双线性Diffie-Hellman问题,从而完善了WZY方案的安全性证明。     

An ID-based multi-signer universal designated multi-verifier signature scheme

In an ID-based universal designated verifier signature scheme, a single signer generates a signature that can only be verified by a designated verifier using a simplified public identity such as an e-mail address. In this paper, we expand the scheme to a multi-user setting for generating and verifying signatures in practical applications. An ID-based multi-signer universal designated multi-verifier signature scheme based on bilinear pairings is proposed that allows a set of multi-signer to cooperatively generate a signature and designate a set of multi-verifier to verify it. The security of the proposed scheme is demonstrated to be resistant to existentially forgery from adaptive chosen-message and chosen-ID attacks under the Bilinear Diffie-Hellman problem.     

多变量强指定验证者签名方案

指定验证者签名在实际的网络信息中有着广泛的应用,验证者不能将签名任意地传播给第三方。强指定验证者签名方案更加强了签名者的隐私,除了指定验证者任何人都不能验证签名的有效性。该文提出一个基于多变量公钥密码体制(MPKCs)的一般强指定验证者签名方案,将多变量公钥密码体制应用到指定验证者签名方案中,如果多变量公钥密码体制在已知攻击,包括代数攻击,线性化攻击,秩攻击和差分攻击等下是安全的,则新方案满足正确性、不可伪造性、不可传递性的安全性要求。并给出一个具体的基于pFLASH签名体制的强指定验证者签名方案,具有明显的效率优势,新方案在量子计算攻击下是安全的。     

Reuse of proofs in software verification

This paper presents a method for automated reuse of proofs in software verification. Proofs about programs as well as proof attempts are used to guide the verification of modified programs, particularly of program corrections. We illustrate the phenomenon of reusability, present an evolutionary verification process model and discuss theoretical and technical aspects. Finally, we report on case studies with an implementation of this method in the Karlsruhe Interactive Verifier (KIV). This research was partly sponsored by the BMFT project KORSO.