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标准模型下高效的基于口令认证密钥协商协议 总被引:1,自引:0,他引:1
基于口令的认证密钥协商协议是利用预先共享的口令协商安全性较高的密钥。现有的基于口令认证密钥协商协议大多需要较大的计算量,或者只在随机预言模型下证明了协议的安全性。该文提出了新的标准模型下基于口令密钥协商协议,协议只需要一个生成元。 与其它标准模型下的协议相比,新协议不需要CPA或CCA2安全的加密方案,因而具有计算复杂度低和协议描述简单的特点。相对于殷胤等人在标准模型下可证安全的加密密钥协商协议一文中提出的协议,新协议将指数运算降低了64%。最后,基于DDH假设,在标准模型下证明了协议的安全性。 相似文献
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2003年,Gentry提出基于认证的公钥加密方案.在基于认证的公钥加密方案中,第三方对认证申请者的公钥和/或身份进行签名,并将签名作为认证发送给申请者,申请者保存该认证作为解密时的部分私钥.接收方对密文解密需要同时拥有第三方对其公钥和/或身份的认证和接收方公钥对应的私钥,因此基于认证的加密方案同时具备基于身份加密方案的公钥可认证性和传统公钥方案中的私钥免撤销性.本文提出一种高效、紧凑的基于认证的公钥混合加密算法,新算法能在非随机预言机模型下被证明满足选择密文攻击安全. 相似文献
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现有会话密钥可托管的ID-AKA(IDentity-based Authenticated Key Agreement)协议要么存在已知安全缺陷,要么是在随机预言模型下可证明安全.基于Boneh等人定义的安全陷门函数,提出一种会话密钥可托管的ID-AKA协议.在ID-BJM模型基础上,扩展定义了ID-AKA协议分析的标准安全模型.扩展模型将安全游戏划分为两个阶段,去除了随机预言机,能完备地模拟不同类型敌手的行为.在扩展模型下,新协议的安全性被规约为多项式时间敌手求解判定性BDH(Bilinear Diffie-Hellman)难题和判定性BDHI(Bilinear Diffie-Hellman Inversion)难题,具有可证明安全性. 相似文献
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一轮Diffie-Hellman密钥交换(One-Round Diff ie-Hellman key exchange,OR-DHKE)协议被认为无法实现完美的前向安全性(Perfect Forward Secrecy,PFS)。基于身份的OR-DHKE协议也是如此,现有研究仅实现了弱的完美 前向安全性(wPFS)。基于Cremers等人对密钥交换协议完美前向安全性的研究,文章提出 一种新的具有完美前向安全的基于身份认证密钥交换方案。文章首先提出一种较弱安全性的 基于身份 OR-DHKE协议π0,然后采用Cremers等人提出的SIG变换方法,将π0转化为具有完美前 向安全的基于身份认 证密钥交换方案π1。文章简要分析了CK、CK+、eCK和eCK-PFS安全模型的异同,在此 基 础上定义了基于身 份认证密钥交换协议分析的强安全模型ID-eCK-PFS。在ID-eCK-PFS模型下,协议π0和π1的安全性被规约为 求解判定性BDH(Decisional Bilinear Diffie-Hellman,DBDH)问题,规约过程未使用随 机预言机,实现了在标准模型下的完美前向安全性和可证明安全性。 相似文献
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基于层级化身份的可证明安全的认证密钥协商协议 总被引:1,自引:0,他引:1
目前基于身份的认证密钥协商协议均以单个私钥生成器(PKG)为可信第三方,但这种系统结构难以满足身份分层注册与认证需求。该文以基于层级化身份的加密(HIBE)系统为基础重构了私钥的组成元素,并利用椭圆曲线乘法循环群上的双线性映射提出一个基于层级化身份的认证密钥协商协议,为隶属于不同层级的云实体提供了安全的会话密钥协商机制。基于CDH(Computational Diffie-Hellman)与GDH(Gap Diffie-Hellman)假设,该文证明了新协议在eCK模型下具有已知密钥安全性、前向安全性和PKG前向安全性,并且能够抵抗基于密钥泄露的伪装攻击。 相似文献
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基于证书的公钥密码体制因其克服了基于身份密码体制和传统公钥密码体制中存在的缺陷,成为一种颇受关注的公钥密码体制。目前大部分基于证书公钥加密算法中都使用了双线性对运算,由于双线性对运算的计算代价高于普通的指数运算,所以构造没有双线性对运算的基于证书加密方案成为当前研究的热点。在原始的证书加密模型的基础上提出了证书公钥概念,并给出了一个不使用双线性对的加密方案。基于判定性Diffie-Hellman困难问题假设,在随机预言模型下方案被证明是IND-CBE-CCA自适应选择密文安全的。由于方案未使用双线性对,故在总体性能上优于现有的方案。 相似文献
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代理重加密方案使一个半可信的代理者将用委托者的公钥加密的密文转换成用受委托者公钥加密的密文,在转换其间代理者不能获得相关的明文信息。基于证书的公钥密码体制克服了传统公钥密码体制和基于身份密码体制的缺点与不足,为此将证书加密体制与代理重加密结合起来,提出了一个在随机预言模型下的适应性选择密文安全的基于证书代理重加密方案。 相似文献
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In this article, based on Chatterjee-Sarkar' hierarchical identity-based encryption (HIBE), a novel identity-based encryption with wildcards (WIBE) scheme is proposed and is proven secure in the standard model (without random oracle). The proposed scheme is proven to be secure assuming that the decisional Bilinear Diffie-Hellman (DBDH) problem is hard. Compared with the Wa-WIBE scheme that is secure in the standard model, our scheme has shorter common parameters and ciphertext length. 相似文献
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针对基于身份公钥密码体制中固有的密钥托管和传统公钥密码系统中证书管理问题,结合基于证书公钥密码系统的优点和消息恢复签名的特点,设计了一种基于证书的带消息恢复的代理签名方案,该方案基于离散对数问题和计算Deffie-Hellman问题假设,可限制代理人滥用代理权力,具有正确性、不可伪造性和不可否认性,最后给出了证明。 相似文献
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针对已有的可证安全的前向安全公钥加密方案仅满足较弱的选择明文安全性,难以满足实际应用的安全需求这一问题,提出了一个新的前向安全公钥加密方案,基于判定性截断q-ABDHE问题的困难性,该方案在标准模型下被证明满足选择密文安全性。在该方案中,解密算法的计算代价和密文的长度独立于系统时间周期总数。对比分析表明,该方案的整体性能优于已有的前向安全公钥加密方案。 相似文献
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In 2010,Liu,et al.proposed a certificateless signcryption scheme in the standard model,but many analyses revealed that Liu's scheme was insecure in fact.To overcome the disadvantages,the scheme was improved and a certificateless generalized signcryption scheme was constructed.In addition,a formal security model for the proposed scheme against the malicious-but-passive KGC attacks was introduced.Furthermore,the proposed scheme was proven to be secure under the decisional bilinear Diffie-Hellman and the computational Diffie-Hellman intractability assumptions in the standard model.Numerical results illustrate that the proposed algorithm is efficient. 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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proposed scheme is provably secure based on the computational Diffie-Hellman (CDH) intractability assumption without relying on the random oracles, and satisfies all the security requirements for a secure proxy signature. 相似文献
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The data encryption standard in perspective 总被引:1,自引:0,他引:1
The Data Encryption Standard (DES) was approved as a Federal Information Processing Standard (FIPS) by the Secretary of Commerce on November 23, 1976. This Standard was developed as a part of the Computer Security Program within the Institute for Computer Sciences and Technology at the National Bureau of Standards (NBS). This paper places this standard in perspective with other computer security measures that can and should be applied to Federal computer systems either before or coincident to using the Data Encryption Standard. In 1972, NBS initiated the standards development effort leading to adoption of the DES. During this period, NBS solicited for algorithms and information upon which a standard could be based, published for comment the algorithm which best satisfied the requirements of an encryption standard, and coordinated the effort with both the potential using communities and supplying communities. This paper outlines the environment surrounding and the history of the Data Encryption Standard and discusses the objectives of additional standards to be developed within the computer security program. 相似文献