共查询到20条相似文献,搜索用时 31 毫秒
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YANG Jun ZHOU Xian-wei QIN Bo-ping 《中国电子科技》2006,4(1):55-58
The EIGamal algorithm, which can be used for both signature and encryption, is of importance in public-key cryptosystems. However, there has arisen an issue that different criteria of selecting a random number are used for the same algorithm. In the aspects of the sufficiency, necessity, security and computational overhead of parameter selection, this paper analyzes these criteria in a comparative manner and points out the insecurities in some textbook cryptographic schemes. Meanwhile, in order to enhance security a novel generalization of the EIGamal signature scheme is made by expanding the range of selecting random numbers at an acceptable cost of additional computation, and its feasibility is demonstrated. 相似文献
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给出了攻击ElGamal类型数字签名方案的一种方法,揭示了签名所需时间与随机参数k取值之间的关系,指出当k值较小时,此类签名方案是不安全的。 相似文献
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Design of generalised ElGamal type digital signature schemes basedon discrete logarithm 总被引:2,自引:0,他引:2
The ElGamal type digital signature schemes have received wide attention recently. ElGamal type signature schemes can provide `subliminal' channel, message recovery, multisignature, etc. The authors investigate the design criteria of ElGamal type signature scheme and develop a complete list of all variations 相似文献
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本文提出了一种称作隐式ElGamal型签名方案的新方案。在这种签名方案中,真实签名被隐蔽起来,签名者仅将隐式签名送签名收方。我们在广义ElGamal型签名方案上构造了许多隐式签名方案。分析表明,隐式ElGamal型签名方案不但较源ElGamal型签名方案更安全,而且可以被用来封闭阈下信道以及同时签发两个不同的消息。 相似文献
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验证者要知道一个证实数字签名的有效性,必须得到一个称为证实者的第三方的帮助与合作。签名者的安全性和证实签名的“不可见性”是一个证实数字签名方案必须具备的两个重要特性。现存的证实签名实现方案,或者是低效的,或者是不安全的。本文首次基于ElGamal签名机制提出一种新的证实数字签名方案,分析表明,该方案是一种安全而高效的证实数字签名实现方案。 相似文献
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本文对两类ElGamal型签名方案的安全性和基于两类签名方案的通行字认证方案进行了分析和讨论。通过对这些问题的研究,可以对两类ElGamal型签名方案的安全性、性能和相互关系有新的认识。 相似文献
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为了加强ElGamal型数字签名方案的安全性,最近祁明等人对两类ElGamal型数字签名方案的安全性和基于两类签名方案的通行字认证方案进行了分析和讨论,并且提出了两类改进型的方案.本文首先指出了他们提出的第一个p型方案是不安全的,攻击者可以伪造任意消息的数字签名.本文证明了广义ElGamal型数字签名方案都不能抵御代换攻击.本文最后还证明了他们提出的两类改进型方案也不能抵御同态攻击,因而并不具有所说的安全性. 相似文献
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A Distributed Key Generation (DKG) protocol is an essential component of threshold cryptosystems required to initialize the
cryptosystem securely and generate its private and public keys. In the case of discrete-log-based (dlog-based) threshold signature
schemes (ElGamal and its derivatives), the DKG protocol is further used in the distributed signature generation phase to generate
one-time signature randomizers (r = gk). In this paper we show that a widely used dlog-based DKG protocol suggested by Pedersen does not guarantee a uniformly random
distribution of generated keys: we describe an efficient active attacker controlling a small number of parties which successfully
biases the values of the generated keys away from uniform. We then present a new DKG protocol for the setting of dlog-based
cryptosystems which we prove to satisfy the security requirements from DKG protocols and, in particular, it ensures a uniform
distribution of the generated keys. The new protocol can be used as a secure replacement for the many applications of Pedersen's
protocol. Motivated by the fact that the new DKG protocol incurs additional communication cost relative to Pedersen's original
protocol, we investigate whether the latter can be used in specific applications which require relaxed security properties
from the DKG protocol. We answer this question affirmatively by showing that Pedersen's protocol suffices for the secure implementation
of certain threshold cryptosystems whose security can be reduced to the hardness of the discrete logarithm problem. In particular,
we show Pedersen's DKG to be sufficient for the construction of a threshold Schnorr signature scheme. Finally, we observe
an interesting trade-off between security (reductions), computation, and communication that arises when comparing Pedersen's
DKG protocol with ours. 相似文献
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本文采用兼容PIC16C72的8位嵌入式微处理器做控制芯片,完成了一种仿ElGamal的数字签名算法。并且与设计的点乘硬件芯片一起构成了一种椭圆曲线公钥制密码系统。该系统工作时钟为20MHz,一秒钟内可以完成10次签名,签名速度与国外见于报道的同类产品相当。 相似文献
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数字移动通信网中的用户认证方案 总被引:3,自引:0,他引:3
刘建伟 《信息安全与通信保密》1995,(1)
本文根据Harn L提出的修正ELGamal签名方案和Rabin的公钥加密体制,提出了一种适用于数字移动通信网的公钥用户认证方案。该方案克服了GSM和CT—2等系统中所采用的秘密密钥方案不够安全的缺点,并具有较低的计算复杂度和较高的安全性。 相似文献
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ID-based signatures from pairings on elliptic curves 总被引:10,自引:0,他引:10
An efficient identity-based signature scheme is presented which makes use of bilinear pairings on elliptic curves. This scheme is similar to the generalised ElGamal signature scheme. The security of the scheme is considered 相似文献
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Due to forward-secure-digital-signature’s capability of effectively reducing loss caused by exposure of secret keys and significant in-application benefits of blind signature aiming at protecting senders’privacy, they have been hot spots for decades in the field of cryptography. Illuminated by the integration of forward secure digital signature and blind signature,based on the variants of ElGamal and assumption of difficulty in solving the discrete logarithm problem in galois field, a forward-secure weak blind signature scheme and a forward-secure strong blind signature scheme are proposed and their security is analyzed thoroughly in this paper. It turns out that forward security, blindness and aptitude of resisting forging attack demonstrated by these two schemes benefit a lot theoretically and practically. 相似文献
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ElGamal数字签名方案的发展与应用 总被引:3,自引:0,他引:3
ElGamal数字签名方案作为目前最为重要的数字签名方案之一,极大地促进了现代密码学的发展。分析了几个主要的ElGamal型数字签名方案的优缺点,并阐述了ElGamal型数字签名方案的一些应用状况。 相似文献
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New signature scheme with message recovery 总被引:1,自引:0,他引:1
A modification is presented of the digital signature scheme of ElGamal (1985) that allows message recovery.<> 相似文献
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在广义ElGarnal签名方案的基础上,基于二元仿射变换构造一些新的强盲签名方案,并对这些方案进行了检验和分析。 相似文献
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基于因数分解和离散对数的数字签名协议 总被引:6,自引:0,他引:6
邵祖华 《信息安全与通信保密》1998,(4)
本文设计了两个数字签名协议,它们的安全性基于因数分解和离散对数的困难性,它们的性能类似于基本的ElGamal数字签名协议和Harn数字签名协议。本文还讨论了几种可能的攻击,证明了它们的安全性高于后两种数字签名协议。 相似文献