增强型数字签名技术在C3I系统中的应用

在C^3I系统中，多舰协同或编队联合作战时的通信信道一般是无线信道，保密机制一般借助专用密码机对报文信息进行加解密处理。这种机制增加了报文收发时的处理环节，增加了时延，降低了信息的时效性。另外，接收方如何鉴别已收报文的真伪及完整性，目前均还未考虑。通过探讨数字签名技术在C^3I系统中的应用问题，提出增强型数字签名模型。该模型在普通数字签名模型的基础上，引入加密机制加强了对消息原文的加密处理，并仅对报文摘要进行签名，提高了信道利用率。该模型可较好地解决C^3I系统中信息传输过程中的安全和报文鉴别问题，而且实用性更强。     

基于ECC的入侵容忍数字签字方案

入侵容忍是网络安全中的一种新方法,该方法保证系统在遭受攻击的情况下信息的机密性、完整性和可用性.本文基于安全的椭圆曲线,结合门限体制、可验证秘密共享体制以及主动秘密共享方案,给出一种新的入侵容忍签字方案.新方案在签名时可以避免密钥重构,防止了密钥的泄漏.     

Lys98群盲签名方案的一个安全缺陷及其改进

1998年Lysyanskaya和Ramzan在国际金融密码会议(FC98)上,将群签名和盲签名结合起来提出第一个群盲签名方案(Lys98),他们认为该方案能够满足抗联合攻击等多种安全需求。本文首先指出Lys98方案是不能抵抗联合攻击的,然后针对它的成员加入协议给出一个简单的联合攻击方案。该攻击证明了在成员加入阶段个别群成员勾结起来可以伪造能产生合法群签名但却无法被跟踪的成员证书。最后本文针对该攻击提出两个改进方案。     

Low cost and reliable anonymity protocols in P2P reputation systems

In peer-to-peer (P2P) reputation systems,each peer's trustworthiness is evaluated based on its pseudonym's rating values given by other peers. Since it is assumed that each peer has a long lived pseudonym,all the transactions conducted by the same peer may be linked by its pseudonym. Therefore,one of the fundamental challenges in P2P reputation systems is to protect peers' identity privacy. In this paper,we present two independent anonymity protocols to achieve all the peers' anonymity by changing pseudonym...     

Provably Secure Short Proxy Signature Scheme from Bilinear Maps

An enhanced formal model of security for proxy signature schemes is presented and a provably secure short proxy signature scheme is proposed from bilinear maps. The proposed proxy signature scheme is based on two short secure signature schemes. One is used for delegating the signing rights and computing the standard signature; the other is used for computing proxy signature. Finally, a security proof of the proposed proxy signature scheme is showed by reducing tightly the security of the proposed proxy signature scheme to the security of the two basic signature schemes. The proposed proxy signature scheme has the shortest ordinary signatures and proxy signatures. Moreover, the proxy signature generation needs no pairing operation and verification needs just two pairing operation.     

A universal composability framework for analysis of proxy threshold signature

The universal composability framework is a new approach for designing and analyzing the security of cryptographic protocols. In this framework, the security of protocols is maintained under a general protocol composition operation. In the paper, we propose the universal composability framework for the analysis of proxy threshold signature and present a universally composable secure proxy threshold signature scheme which is the first one in this area. The proposed scheme is suitable for the mobile agents, which should migrate across different environment through network. Furthermore, we give the concrete analysis of the reduction to prove the security of the proposed scheme.     

雷达对抗目标信号特征研究

雷达对抗目标信号特征在对雷达对抗目标识别中占有关键作用。文章对雷达对抗目标信号特征做了总的阐述。同时从两个方面分别对常见的信号特征参数进行分析。分析了目标信号细微特征产生的原因,给出了个体特征参数应具有的特征条件。分析了目标细微特征用于个体识别。对雷达对抗目标的信号特征问题进行了总结与展望。     

基于椭圆曲线的不可否认门限代理签名方案

针对已有的门限代理签名方案不能有效地抵抗签名人协作攻击和伪造攻击,以及在某些场合实用性不强的缺点提出了改进方案.在代理签名生成阶段要求每个实际签名人提供自己的私钥信息,在形成的代理签名中不仅包含每个代理签名人的秘密信息,还包含了每个实际签名人的秘密信息,从而能有效抵抗协作攻击和伪造攻击.另外,用椭圆曲线密码机制替换了已有的方案中用的ElGamal离散对数密钥机制,使系统效率更高.     

数字签名技术及其在校园管理信息系统中的应用

数字签名是一种重要的安全机制,用来提供通信双方的不可否认服务,已经得到了广泛的应用.阐述数字签名的概念、功能和实现,最后提出一种在校园管理信息系统中实现数字签名的方案.     

一种群签名方案的安全缺陷及其改进

最近Lee和Chang提出了一种基于离散对数的高效群签名方案。然而,该方案不能抵御伪造攻击,同时不具有不可链接性的特点。敖青云等人提出一种改进的方案,希望能克服Lee-Chang方案的不足。本文首先指出了敖青云等人提出的群签名方案仍然是不安全的,基于Tseng方案,提出了一种改进的群签名方案,并对其安全性进行了简要分析。