共查询到18条相似文献,搜索用时 109 毫秒
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对一个具有消息恢复的指定接收者的代理盲签名方案提出安全分析,指出方案存在以下安全缺陷:由于模运算错误,使得方案不满足可验证性;对代理签名者而言,不满足方案的盲性;代理签名者可以生成对任意消息的有效签名,即方案不满足不可滥用性。 相似文献
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通过对柳等提出的代理盲签名方案进行安全性分析,指出方案存在以下安全缺陷:不诚实的原始签名人可以伪造代理签名密钥,即方案不满足强不可伪造性;代理签名人可以将盲消息的签名和原消息的签名联系起来,即方案是可链接的。针对这些安全缺陷,提出了一种改进的代理盲签名方案。通过修改代理授权方程和盲签名过程,新方案可以抵抗原始签名人的伪造攻击,且满足非关联性。 相似文献
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秦宝东 《计算机工程与应用》2009,45(3):104-105
高炜等人和Yu Bao-zheng等人分别提出了两种基于离散对数的代理盲签名方案。对这两种方案进行了安全性分析。研究表明,这两种方案存在以下不足之处:高炜等人的代理盲签名方案是对谭等方案的改进,新的方案仍然具有可连接性,即代理签名者可以从一个合法的代理盲签名中恢复出此签名的中间值从而跟踪消息的拥有者。Yu Bao-zheng等人的代理盲签名方案同样具有可连接性的缺点。除此之外,用户可以通过自己持有的代理盲签名信息恢复出代理签名私钥,从而可以冒充代理签名者伪造消息m的代理盲签名或者直接利用一个合法的代理盲签名伪造出其它消息的合法代理盲签名。为了避免上述不足之处,给出了一个防止代理签名者连接性攻击的改进方案。 相似文献
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给出一种可容忍信息泄露的指定验证者盲代理签名方案,它具有一些代理签名方案的新特点:匿名性和可追踪性。指定验证者在验证代理签名之后只能确信代理签名是代表原始签名者的签名而无法确定代理签名者身份;当出现争议时,指定验证者可通过代理群管理员追查出代理签名者的身份。提出的方案较好地解决了基于身份指定验证者签名中的密钥托管问题。与同类方案相比,签名和验证次数少、交互次数更少。 相似文献
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Kyung-Ah Shim Author Vitae 《Computers & Electrical Engineering》2011,37(2):180-186
A proxy signature enables an original signer to delegate its signing capability to a proxy signer and the proxy signer can sign a message on behalf of the original signer. Later, anyone can verify the validity of proxy signatures. The “public-verifiable” property of the proxy signature is not suitable in some applications in which a proxy signed message may be personally or commercially sensitive. A designated verifier proxy signature scheme is suitable for these environments. In this paper, we propose a provably secure short designated verifier proxy signature scheme in the random oracle model under the Bilinear Diffie-Hellman assumption. 相似文献
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A strong designated verifier signature scheme makes it possible for a signer to convince a designated verifier that she has signed a message in such a way that the designated verifier cannot transfer the signature to a third party, and no third party can even verify the validity of a designated verifier signature. We show that anyone who intercepts one signature can verify subsequent signatures in Zhang-Mao ID-based designated verifier signature scheme and Lal-Verma ID-based designated verifier proxy signature scheme. We propose a new and efficient ID-based designated verifier signature scheme that is strong and unforgeable. As a direct corollary, we also get a new efficient ID-based designated verifier proxy signature scheme. 相似文献
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Recently, Kang et al. proposed a new identity-based strong designated verifier signature scheme (ID-SDVS) and identity-based designated verifier proxy signature scheme (ID-DVPS). They claimed that their schemes are unforgeable. However, we found out that their schemes are universally forgeable in the sense that anyone can forge valid ID-SDVS and ID-DVPS on an arbitrary message without the knowledge of the secret key of either the signer or the designated verifier. Finally, we propose an improved ID-SDVS which is unforgeable. We give formal security proof of universal unforgeability of our scheme. We also give an improved ID-DVPS. 相似文献