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对一种基于身份的已知签名人的门限代理签名方案的分析 总被引:1,自引:0,他引:1
在TAMC'06上,Bao等人以双线性对为工具,首次提出了一种基于身份的已知签名人的门限代理签名方案(以下标记为BCW方案),并得出了满足强不可伪造性以及原始签名人发送签名了的授权证书时并不需要安全信道等安全性结论。本文对BCW方案进行了安全性分析,成功地给出了一种攻击,攻击者通过公开渠道获得一个合法的原始签名人发送给代理签名人的签名了的授权证书以及代理签名人已经生成的一个有效的代理签名后,能够伪造出一个新的对相同消息的代理签名,而原始签名人变为攻击者自己。由于验证者并不能验证代理签名人到底是代表谁生成了代理签名, 这样,攻击者就获得了与合法原始签名人相同的权益。为了避免这种攻击,本文提出了改进的措施,分析表明,改进措施能有效地弥补了该方案的安全缺陷。 相似文献
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一种代理多签名体制的安全性分析 总被引:3,自引:0,他引:3
对Ji和Li的基于椭圆曲线离散对数问题的代理多签名体制提出了两个伪造攻击。利用这两个伪造攻击,任何一个原始签名人都能伪造出一个有效的代理多重数字签名。并对Ji和Li的代理多签名体制进行了改进,提出了新的安全的基于椭圆曲线离散对数问题的代理多签名体制。 相似文献
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本文把矢量空间秘密共享方案与多重签名方案结合起来,提出了一种新的签名方案,即矢量空间秘密共享-多重签名方案,并对该方案的安全性进行了分析.在该方案中,任何参与者的授权子集能容易地产生群签名,而参与者的非授权子集不可能产生有效的群签名,验证者可通过验证方法验证个体签名和群签名的合法性.该方案能保证一个参与者的授权子集的群签名不能被其他参与者子集所伪造,而且可以跟踪被怀疑的伪造者并将其曝光.该方案能抵御各种可能的攻击. 相似文献
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本文把矢量空间秘密共享方案与多重签名方案结合起来,提出了一种新的签名方案,即矢量空间秘密共享-多重签名方案,并对该方案的安全性进行了分析。在该方案中,任何参与者的授权子集能容易地产生群签名,而参与者的非授权子集不可能产生有效的群签名,验证者可通过验证方法验证个体签名和群签名的合法性。该方案能保证一个参与者的授权子集的群签名不能被其他参与者子集所伪造,而且可以跟踪被怀疑的伪造者并将其曝光。该方案能抵御各种可能的攻击。 相似文献
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在一个(t,n)门限代理签名体制中,原始签名者可以将他的签名权利以门限的方式委托给n个代理签名者,使得至少f个代理签名者合作可以代表他对消息签名,而至多t-1个代理签名人不能产生有效的代理签名.文中借助于RSA秘密共享的思想,构造了一个安全、有效的RSA门限代理签名方案. 相似文献
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A new multi-proxy signature from bilinear pairing 总被引:2,自引:0,他引:2
Li Sujuan Zhang Futai 《电子科学学刊(英文版)》2007,24(1):90-94
Proxy signatures are very useful tools when one needs to delegate his/her signing capability to other parties. In this paper, a new multi-proxy signature scheme is proposed. The new scheme is constructed from bilinear pairings using Boneh, Lynn, and Shacham's (BLS) short signatures. The proxy key for the proxy group is just a short signature on the proxy warrant generated by the original signer. Due to the use of short signatures, our scheme is not only efficient, but also satisfies all the security requirements of the strong proxy signature. 相似文献
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YU Yong YANG Bo State Key Laboratory of ISN Xidian University Xi’an China SUN Ying College of information South China Agricultural University Guangzhou China 《中国邮电高校学报(英文版)》2007,14(2):69-74
Proxy signature schemes allow an original signer to delegate his signing rights to a proxy signer. However, many proxy signature schemes have the defect which is the inability to solve the proxy revocation problem. In this article, we firstly propose an identity-based threshold signature scheme and show that it has the properties of unforgeability and robustness. In our threshold signature scheme, we adopt such a method that the private key associated with an identity rather than the master key is shared. Then, based on the threshold signature scheme, an identity-based mediated proxy signature scheme is proposed where a security mediator (SEM) is introduced to help a proxy signer to generate valid proxy signatures, examine whether a proxy signer signs according to the warrant, and check the revocation of a proxy signer. It is shown that the proposed scheme satisfies all the security requirements of a secure proxy signature. Moreover, a proxy signer must cooperate with the SEM to generate a valid proxy signature, which makes the new scheme have an effective and fast proxy revocation . 相似文献
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Multi-proxy signature is a scheme that an original signer delegates his or her signing capability to a proxy group.In the scheme,only the cooperation of all proxy signers in the proxy group can create a signature on behalf of the original signer.Jin and Wen firstly defined the formal security model of certificateless multi-proxy signature(CLMPS) and proposed a concrete CLMPS scheme.However,their construction has three problems:the definition of the strengthened security model is inaccurate,the concrete signature scheme has a security flaw,and the proof of the security is imperfect.With further consideration,a remedial strengthened security model is redefined,and an improved scheme is also proposed,which is existentially unforgeable against adaptively chosen-warrant,chosen-message and chosen-identity attacks in the random oracles.In this condition,the computational Diffie-Hellman(CDH) assumption is used to prove full security for our CLMPS scheme. 相似文献
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Hu Bin Jin Chenhui 《电子科学学刊(英文版)》2006,23(1):54-57
Proxy signature is a special digital signature which enables a proxy signer to sign messages on behalf of the original signer. This paper proposes a strongly secure proxy signature scheme and a secure multi-proxy signature scheme based on elliptic curve cryptosystem. Contrast with universal proxy signature schemes, they are secure against key substitute attack even if there is not a certificate authority in the system, and also secure against the original signer's forgery attack. Furtherlnore, based on the elliptic curve cryptosystem, they are more efficient and have smaller key size than other system. They can be used in electronics transaction and mobile agent environment. 相似文献