共查询到17条相似文献,搜索用时 93 毫秒
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利用椭圆曲线上的双线性对,提出一个基于身份的签密方案。在新方案中,接收者收到一个签密消息,在验证该消息签名的合法性后,再对消息进行恢复。在安全性方面,新方案具有机密性、不可伪造性、公开可验证性、鲁棒性;在计算量和通信成本方面,新方案中只需要进行1次模指数运算、2次双线性对运算和1次双线性对预运算,签密产生的密文长度为2|G1|+|m|,总成本比已有的基于身份的签密方案耗费少,从而有效实现了对消息的认证和保密。 相似文献
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异构签密可以保证不同公钥密码系统之间数据传输的机密性和不可伪造性。本文定义了从无证书公钥密码环境到传统公钥密码环境(CLPKC→TPKI)异构签密方案的形式化模型,并利用双线性对提出了一个CLPKC→TPKI异构签密方案。在随机预言模型下,基于计算Diffie-Hellman和修改逆计算Diffie-Hellman困难假设,证明方案满足内部安全的机密性和不可伪造性。同时,方案满足密文匿名性,可以有效地保护收发双方的身份隐私。方案使用不同的密码系统参数,更接近于实际应用环境。与已有异构签密方案相比,方案的效率较高,适合于收发双方身份保密和带宽受限的应用需求。 相似文献
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异构签密可以保证异构密码系统之间数据的机密性和不可伪造性。分析现有的异构签密方案,发现它们只针对单个消息,无法实现批验证。聚合签密能够把不同用户对多个消息产生的签密密文同时发送给接收者,而且可以提供批量验证,降低验证开销。该文提出一个传统公钥密码-无证书公钥密码异构聚合签密方案,该方案不仅能够保证传统公钥密码(TPKI)和无证书公钥密码(CLPKC)系统间通信的机密性和认证性,而且聚合验证时不需要双线性对。在随机预言模型下,基于间隙双线性Diffie-Hellman困难问题、计算Diffie-Hellman困难问题和离散对数问题,证明该方案满足自适应性选择密文攻击下的不可区分性和自适应选择消息下的不可伪造性。 相似文献
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签密能够在一个合理的密码协议中同时完成数字签名和公钥加密两种功能,减少了通信成本.利用椭圆曲线的双线性对性质,提出了一种基于身份的签密方案.该方案同时满足签密方案所具有的机密性、不可伪造性、前向安全性,而且能抵抗信息接收方的欺骗攻击.通过分析和比较,该方案具有很好的安全性和较高的效率. 相似文献
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身份属性泄漏是最严重的云计算安全威胁之一,为解决该问题,提出了一种基于环签密的身份属性保护方案.该方案以云服务的数字身份管理为研究对象,论述了去中心化的用户密钥分割管理机制,用户自主选择算子在本地生成并存储密钥,从而令注册管理者(registrar)无法获得用户完全私钥,达到消除证书管理负载的目的.另外,本方案以用户访问权限为中心设计身份属性盲环签密验证机制,令用户和CSP组成环,基于环和自身属性用户可对消息子线性盲签密以及非交互公开密文验证,用以阻止多个CSP共谋导致的身份属性泄露场景,从而保护身份属性的完整性和机密性.最后,给出密文和属性强不可伪造、盲性机制的证明结果,在DBDH困难问题假设和适应性选择密文攻击下,方案中的用户可生成3个完全私钥组件,成功阻止环成员身份伪装.为验证系统有效性,围绕身份属性保护方案的综合负载问题对盲环签密算法进行性能评估,并对比同类算法以证实系统优化结果. 相似文献
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两种签密方案的安全性分析及改进 总被引:1,自引:0,他引:1
签密是能够在同一算法中提供认证性和机密性的密码方案,而所需要的计算量、通信成本和密文长度比先签名后加密的分开来实现要低,有较多的实际应用需求。多签密方案是多个签密者对同一明文执行签密操作。该文分析了两个签密方案:Li等(2006)提出的签密方案和Zhang等(2008)提出的多签密方案,并通过选择明文攻击证明二者不能不具有语义安全性,并在此基础上提出了改进的方案,采用隐藏消息明文方法抵抗选择明文攻击,采用多签密成员签名认证的方法防止多成员签密密文被篡改,可抵抗选择明文攻击和选择身份攻击,达到语义安全性。 相似文献
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The efficiency of computation is one of the prime concerns in public key cryptography. The notion of online/offline framework speeds up the process of encryption and signing. In this paper, we propose the first attribute‐based online/offline signcryption scheme that is able to provide fine‐grained data access control with confidentiality, authenticity, signer anonymity, and public verifiability. The scheme supports large attribute universe and monotone Boolean function predicates. The size of the system public parameters in our scheme is constant, and the selective security of the scheme is realized in random oracle model. Note that, to the best of our knowledge, there is no normal attribute‐based signcryption scheme satisfying all the aforementioned functionality. 相似文献
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多方签名加密体制是对签名加密体制的扩展,即多个签名者共同对消息进行签名加密操作。文章首先分析了现有的多方签名加密体制存在的缺陷,然后讨论了一种新的多方签名加密体制。该体制不仅能够有效实现消息机密性、消息不可伪造性、不可否认性及强健性等安全服务,而且可以实现消息灵活性、次序灵活性、消息可验性以及次序可验性。因此,该体制适用于保护消患及多个签名者免遭恶意攻击。 相似文献
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Formal Proofs for the Security of Signcryption 总被引:2,自引:0,他引:2
Signcryption is an asymmetric cryptographic method that provides simultaneously both message confidentiality and unforgeability
at a low computational and communication overhead. In this paper we propose realistic security models for signcryption, which
give the attacker power to choose both messages/signcryptexts as well as recipient/sender public keys when accessing the signcryption/unsigncryption
oracles of attacked entities. We then show that Zheng's original signcryption scheme is secure in our confidentiality model
relative to the Gap Diffie-Hellman problem and is secure in our unforgeability model relative to a Gap version of the discrete
logarithm problem. All these results are shown in the random oracle model. 相似文献
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In view of the existing efficiency and security problems of lattice based signcryption,with the ABB16’s signature scheme ring-TESLA,a signcryption scheme without trapdoor named RLWE-SC was constructed,which achieved indistinguish ability against adaptive chosen cipher text attack (IND-CCA2) security and strongly existential unforgeability against chosen message attack (SUF-CMA) security respectively in terms of confidentiality and authentication based on the problem of learning with errors on ring.The size of the public and private keys was optimized by the construction on the ring.The complex trapdoor generation and preimage sample calculation was avoided by the structure without trapdoor.Efficiency analysis and experiment shows that RLWE-SC has better computational and communication performance than other similar lattice-based signcryption schemes with the same security strength. 相似文献
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在云计算应用中,确保消息的机密性和不可伪造性,同时判断不同密文对应明文的等价性显得至关重要。具有密文等值测试功能的签密方案可以实现此类安全目标。该文基于无证书公钥密码环境,设计了一个具有密文等值测试功能的无证书签密方案(CLSCET)。首先,提出了无证书密文等值测试签密方案的框架和安全模型,定义了两类具有不同攻击能力的敌手和3类安全目标。然后构造了具体的无证书密文等值测试签密方案,并分析了方案的正确性。最后,基于随机预言模型,证明该文方案满足选择密文攻击下的单向性(OW-CCA)、选择密文攻击下的不可区分性(IND-CCA2)和选择消息攻击下的不可伪造性(EUF-CMA)安全。与现有近似方案相比,该文方案满足IND-CCA2的机密性、EUF-CMA的不可伪造性和OW-CCA的密文单向性。 相似文献
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In order to solve the problem of secure transmission of messages with multiple receivers,a code-based generalized signcryption scheme with multi-receiver was designed.Firstly,a multi-encrypted McEliece scheme that can meet the security of IND-CCA2 was designed.Combined with the CFS signature scheme,the multi-receiver signcryption and generalized signcryption scheme based on code were designed.The security analysis shows that the multi-receiver generalized signcryption scheme can meet the security of IND-CCA2 in terms of confidentiality and can meet EUF-CMA security in terms of unforgeability.Compared with other similar multi-receiver signcryption schemes,the proposed scheme does not include exponential,bilinear pairing operations,etc.,and has high computational efficiency and the advantage of anti-quantum computing.Compared with the method of signing-then-encrypting method,the proposed scheme has the smaller private key and higher efficiency. 相似文献