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通过分析基于大整数分解、离散对数和双线性对等数学问题的特殊可传递签名方案,抽象出了可传递签名实现方法的共性。以此为基础,提出了一个基于同态加密体制的通用可传递签名方案,该方案利用同态加密体制能支持密文运算的特性实现了可传递签名及验证的一般模型,为基于同态密码体制构造安全可靠的可传递签名方案提供了一种通用框架。其次,通过适当定义安全目标和设计安全性实验,完成了该通用可传递签名方案的可证明安全性,指出若使用的同态加密方案是CPA安全而标准签名是CMA安全的,则所提出的方案就达到CMA安全。最后,给出了该通用可传递签名方案并进行了性能分析与比较。 相似文献
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一个安全有效的RSA门限签名体制 总被引:2,自引:2,他引:0
提出一种新的RSA门限签名体制,具有如下性质:(1)利用知识证明构造子签名方案,从而子签名是安全的;(2)组签名的安全性是基于RSA问题及离散对数问题;(3)可以对签名者的身份进行追踪。 相似文献
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在要求高效的密钥管理和中等的安全性的情况下,基于身份公钥密码已成为代替基于证书的公钥密码的一个很好的选择.本文在基于身份系统中,引入少数几个采用公钥证书实体充当裁决者,从而提出混合可验证加密签名的概念,并在Cheon基于身份签名体制的基础上,构造了一个有效的混合可验证加密签名体制;随后,本文讨论了混合可验证加密签名体制的安全模型,并在随机谕示模型下,基于双线性映射的计算性Diffie-Hellman问题难解性假设,证明本文体制是可证安全的.本文体制可用于构造基于身份的优化公平签名交换协议,这在电子商务等领域有着广泛的应用. 相似文献
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盲签名是一种重要的密码与计算机网络安全技术,它的使用可以保证所传送的信息不被篡改和伪造。在盲签名方案中,消息的内容对签名者是不可见的,签名被泄露后,签名者不能追踪其签名。论文基于RSA密码体制,利用扩展Euclidean算法构造了一种不可跟踪盲签名方案。 相似文献
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信息安全技术是保障各种网络应用正常运作的必要支撑,而身份认证是信息安全保障技术的重要组成部分。丈中简单分析了传统网络身份认证技术存在的安全缺陷,然后介绍了生物特征识别技术及其国内外应用情况。最后提出了一种把生物特征识别技术与公钥密码技术相结合的多层次身份认证方案,该方案解决了传统身份认证方案的部分缺点,增强了身份认证安全性,为实现更为安全可靠的网络安全体系提供技术支撑。 相似文献
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We present a cryptographically sound security proof of the well-known Needham-Schroeder-Lowe public-key protocol for entity authentication. This protocol was previously only proved over unfounded abstractions from cryptography. We show that it is secure against arbitrary active attacks if it is implemented using standard provably secure cryptographic primitives. Nevertheless, our proof does not have to deal with the probabilistic aspects of cryptography and is, hence, in the scope of current automated proof tools. We achieve this by exploiting a recently proposed Dolev-Yao-style cryptographic library with a provably secure cryptographic implementation. Besides establishing the cryptographic security of the Needham-Schroeder-Lowe protocol, our result exemplifies the potential of this cryptographic library and paves the way for the cryptographically sound verification of security protocols by automated proof tools. 相似文献
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In response to the current need for fast, secure and cheap public-key cryptography, we propose an interactive zero-knowledge
identification scheme and a derived signature scheme that combine provable security based on the problem of computing discrete
logarithms in any group, short keys, very short transmission and minimal on-line computation. This leads to both efficient
and secure applications well suited to implementation on low cost smart cards. We introduce GPS, a Schnorr-like scheme that
does not require knowledge of the order of the group nor of the group element. As a consequence, it can be used with most
cryptographic group structures, including those of unknown order. Furthermore, the computation of the prover's response is
done over the integers, hence can be done with very limited computational capabilities. This paper provides complete security
proofs of the identification scheme. From a practical point of view, the possible range of parameters is discussed and a report
on the performances of an actual implementation on a cheap smart card is included: a complete and secure authentication can
be performed in less than 20 milliseconds with low cost equipment. 相似文献
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J. H. Loxton David S. P. Khoo Gregory J. Bird Jennifer Seberry 《Journal of Cryptology》1992,5(2):139-150
The RSA public-key encryption system of Rivest, Shamir, and Adelman can be broken if the modulus, R say, can be factorized. However, it is still not known if this system can be broken without factorizing R. A version of the RSA scheme is presented with encryption exponent e 3 (mod 6). For this modified version, the equivalence of decryption and factorization of R can be demonstrated.Research supported in part by a grant from the ATERB.Research supported in part by a grant from the ACRB. 相似文献
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针对已有的可证安全的前向安全公钥加密方案仅满足较弱的选择明文安全性,难以满足实际应用的安全需求这一问题,提出了一个新的前向安全公钥加密方案,基于判定性截断q-ABDHE问题的困难性,该方案在标准模型下被证明满足选择密文安全性。在该方案中,解密算法的计算代价和密文的长度独立于系统时间周期总数。对比分析表明,该方案的整体性能优于已有的前向安全公钥加密方案。 相似文献
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关于有限域(F)p上多项式RSA的安全性和RSA的新模拟 总被引:3,自引:1,他引:2
本文首先指出有限域Fp上多项式RSA是不安全的,然后给出了RSA在Zr(r=pq)中的两个新模拟。两个新体制的安全性将主要基于大整数的分解 相似文献
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一种基于RSA的数字图象加密技术及其快速实现 总被引:1,自引:0,他引:1
RSA公钥密码体制的安全性依赖于大整数因数分解的困难性,目前安全素数产生难度大,运算时间长。文章根据素数的特殊表示法研究了一种高速的安全素数算法,针对当今的信息安全问题和数字图像的特点,提出了一种基于图像信息摘要和RSA的图像加密技术,利用图像信息摘要构造图像像素置乱矩阵并对图像像素矩阵进行置乱后再运用RSA公钥加密算法对置乱后的图像快速加密。 相似文献
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Security Arguments for Digital Signatures and Blind Signatures 总被引:85,自引:1,他引:84
Since the appearance of public-key cryptography in the seminal Diffie—Hellman paper, many new schemes have been proposed
and many have been broken. Thus, the simple fact that a cryptographic algorithm withstands cryptanalytic attacks for several
years is often considered as a kind of validation procedure. A much more convincing line of research has tried to provide
``provable' security for cryptographic protocols. Unfortunately, in many cases, provable security is at the cost of a considerable
loss in terms of efficiency. Another way to achieve some kind of provable security is to identify concrete cryptographic objects,
such as hash functions, with ideal random objects and to use arguments from relativized complexity theory. The model underlying
this approach is often called the ``random oracle model.' We use the word ``arguments' for security results proved in this
model. As usual, these arguments are relative to well-established hard algorithmic problems such as factorization or the discrete
logarithm.
In this paper we offer security arguments for a large class of known signature schemes. Moreover, we give for the first time
an argument for a very slight variation of the well-known El Gamal signature scheme. In spite of the existential forgery of
the original scheme, we prove that our variant resists existential forgeries even against an adaptively chosen-message attack.
This is provided that the discrete logarithm problem is hard to solve.
Next, we study the security of blind signatures which are the most important ingredient for anonymity in off-line electronic
cash systems. We first define an appropriate notion of security related to the setting of electronic cash. We then propose
new schemes for which one can provide security arguments.
Received 24 October 1997 and revised 22 May 1998 相似文献