共查询到10条相似文献,搜索用时 109 毫秒
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基于属性的密码体制是基于身份密码体制的泛化和发展,它将身份扩展为一系列属性的集合,具有更强的表达性,并且拥有相同属性的成员自动组成一个环,便于隐匿签名者身份。通过对现有的基于属性门限环签名方案的深入分析,发现这些方案虽然满足匿名性要求,但拥有互补属性的恶意用户可以通过合谋伪造出有效签名。为弥补上述缺陷,首先给出基于属性门限环签名的不可伪造性、不可区分性及抗合谋攻击性的形式化定义,然后给出一个基于属性的抗合谋攻击可变门限环签名方案,其安全性可归约为CDH(computational Diffie-Hellman)困难问题。所提方案通过在用户属性密钥中引入互不相同的秘密随机因子的方法,防止合谋攻击者利用组合私钥的方式伪造签名。在随机预言机模型下,方案被证明能够抵抗适应性选择消息的存在性伪造及合谋攻击,并具有相同签名属性集用户间的不可区分性。与同类方案相比,新方案还具备更高的运算效率。 相似文献
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利用"乘法型共享技术",Langford给出了一种无可信中心的(t2-t 1,n)门限DSS签名方案。结合"加法型共享技术"和"乘法型共享技术"的思想,文中提出了一种新的无可信中心门限DSS签名方案,与(t2-t 1,n)门限签名方案相比较,该方案只需2t-1个签名者。 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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Faguo Wu Wang Yao Xiao Zhang Wenhua Wang Zhiming Zheng 《International Journal of Communication Systems》2019,32(3)
Proxy signature scheme is an important cryptographic primitive, for an entity can delegate his signing right to another entity. Although identity‐based proxy signature schemes based on conventional number‐theoretic problems have been proposed for a long time, the researchers have paid less attention to lattice‐based proxy signature schemes that can resist quantum attack. In this paper, we first propose an identity‐based proxy signature scheme over Number Theory Research Unit (NTRU)‐lattice. We proved that the proposed paradigm is secure under the hardness of the γ‐shortest vector problem on the NTRU lattice in random oracle model; furthermore, the comparison with some existing schemes shows our scheme is more efficient in terms of proxy signature secret key size, proxy signature size, and computation complexity. As the elemental problem of the proposed scheme is difficult even for quantum computation model, our scheme can work well in quantum age. 相似文献