共查询到19条相似文献,搜索用时 140 毫秒
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利用椭圆曲线上的双线性对,以一种新的基于身份的门限签名方案为基础,提出了一种无需可信中心的门限签名方案。新方案密钥生成只需成员之间相互协商完成,解决了密钥托管的问题。在标准模型下对该方案进行安全性证明,验证表明该方案具有健壮性和不可伪造性。 相似文献
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提出一种门限代理盲签名方案。该方案是代理盲签名与门限签名的有机集成,解决了已有代理盲签名方案中代理签名人的权利过于集中的问题,且所有的通信都不需要使用安全的秘密通道,可在公共信道上进行。方案中所有协议都是基于椭圆曲线密码体制构造的,使得密钥尺寸较小,执行效率更高。 相似文献
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门限签名能够分散签名权力,比普通单人签名具有更高的安全性。目前大多数门限签名方案都存在密钥托管的问题。针对一种新的基于身份的门限签名方案存在的安全性问题,利用椭圆曲线上的双线性对,文中提出了一个改进的方案。新方案由私钥生成中心和签名成员合作生成密钥,由此防止了PKG伪造签名,较好地解决了密钥托管的问题。在标准模型下对该方案进行了安全性证明,表明该方案是不可伪造的和健壮的。与已有的门限签名方案相比,安全性有较大的提高,效率没有明显的降低。 相似文献
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文中采用双线性对的签名和验证方式,提出了一种基于身份的多重代理盲签名方案。它综合了多重代理签名和盲签名的优点,能够有效地防止授权人冒充多重代理人对消息进行签名。 相似文献
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通过对Qian-cao-xue的基于双线性映射的的门限代理签名方案分析,发现该方案并不满足强不可伪造性,任何人包括原始签名人可以伪造一个有效的代理签名,同时该方案也不能抵抗原始签名人改变攻击.在此基础上提出了改进的门限代理签名方案(方案1),改进的方案克服了原方案的安全缺陷.并把矢量空间秘密共享和多重代理签名结合起来,构建了一种更为广泛的基于访问结构的多重代理签名(方案2).门限代理签名方案(方案1)成为方案2的特殊情形.方案2中任何参与者的授权子集能产生多重代理签名,而非参与者不可能产生有效的多重代理签名,接收者可以通过验证方法验证个体代理签名和多重代理签名的合法性,而且能保证任何参与者都能检测出错误的子秘密.能抵御各种可能的攻击. 相似文献
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盲签名和代理签名在密码学中有各自的特殊用途。结合二者的优点,利用椭圆曲线上的Weil配对的双线性性质,在基于身份的签名基础上构造了一种改进基于身份的代理盲签名方案。该方案继承了前人的基于身份的代理盲签名方案的优点同时,运算效率进一步提高,代理人受到进一步的保护。最后对该方案的安全性进行了简要分析,从而证明了该方案是可行的。 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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匿名代理签名方案的研究与改进 总被引:6,自引:1,他引:6
对谷利泽等提出的匿名代理签名方案进行密码学分析,指出该方案是不安全的,不能抵抗原签名人的伪造攻击和公钥替换攻击,并给出改进的匿名代理签名方案。改进的方案具有不可否认性,以及抵抗原签名人的伪造攻击和公钥替换攻击等优点。 相似文献
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User revocation is necessary to the practical application of identity-based proxy re-signature scheme.To solve the problem that the existing identity-based proxy re-signature schemes cannot provide revocation functionality,the notion of revocable identity-based proxy re-signature was introduced.Furthermore,the formal definition and security model of revocable identity-based proxy re-signature were presented.Based on proxy re-signature scheme and binary tree structure,a revocable identity-based proxy re-signature scheme was proposed.In the proposed,scheme,the user's signing key consists of two parts,a secret key and an update key.The secret key transmitted over the secure channel is fixed,but the update key broadcasted by the public channel is periodically changed.Only the user who has not been revoked can obtain the update key,and then randomize the secret key and update the key to generate the corresponding signature key of the current time period.In the standard model,the proposed scheme is proved to be existentially unforgeable against adaptive chosen-identity and chosen-message attacks.In addition,the proposed scheme has properties of bidirectionality and multi-use,and can resist signing key exposure attacks.The analysis results show that the proposed scheme can efficiently revoke the user and update the user’s key,and thus it has good scalability. 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
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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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In order to solve the problem of message authentication under the conditions of the ship ad-hoc network (SANET),a signature scheme that does not depend on trusted certificate authorities and tamper-proof devices (TPD) was proposed by using the threshold proxy signature scheme and the properties of bilinear pairings.The proposed scheme used the dual-proxy key and the threshold signature mechanism to enable the ship nodes calculate the message signature in polynomial time.Moreover,the security of the scheme was also proved under the random oracle model.The performance analysis results show that the proposed scheme can meet the requirement of strong proxy signature under the premise of guaranteeing correctness,and has lower computational cost and communication cost. 相似文献