排序方式: 共有130条查询结果,搜索用时 302 毫秒
81.
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
82.
签密是一种能够同时保证机密性和认证性的新颖体制,但已有方案的通信效率较低,成为影响签密广泛应用的主要问题之一。基于BLS签名,构造了一个具有短密文属性的高效签密方案。该方案在Random Oracle模型和GDH假设之下是可证明安全的。明文数据率在当前的安全参数下可达76%,是已知方案中密文长度最短的方案,特别适用于带宽受限场合的安全通信。 相似文献
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Ring signcryption enables a user to send a message confidentially and authentically to a specific receiver in an anonymous way. One of the main reasons for the slow adoption of identity based cryptography is the inherent key escrow problem. In this paper a new certificateless ring signcryption scheme from pairings is presented. It is escrow free in that no KGC is able to decrypt ciphertexts itself. We then formally prove the security of the new scheme in the random oracle model IND CCA2 and EUF CMA. 相似文献
85.
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
86.
针对无线传感器网络中传感器节点能量和计算能力的局限性,本文在Waters-IBE的基础上,提出了一种基于身份的在线/离线加密算法.该算法将加密过程划分为两个阶段:离线阶段和在线阶段.离线阶段由PKG或基站完成,在获得接收者身份和将要加密的消息之前可进行大量复杂运算;在线阶段在节点中只需进行简单运算就可加密消息.在完全模型下可证明算法是CPA安全的.仿真实验表明,算法减轻了节点中的运算量并降低了运算时间,从而更加适用于无线传感器网络. 相似文献
87.
分析了一个在格理论框架下构建的基于身份的代理签名方案,指出方案的安全性证明存在缺陷,并没有实现其所声称的签名不可伪造性的证明,针对方案证明中存在的问题,引入新的参量,重新设定系统参数,改变相应的查询应答方式,弥补了证明缺陷,完成了签名不可伪造性的证明。 相似文献
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In an open network environment, the protection of group communication is a crucial problem. In this article, a novel broadcast group-oriented signcryption scheme is presented for group communication scenarios in distributed networks. Anyone in this scheme can signcrypt a message and distribute it to a designated group, and any member in the receiving group can unsigncrypt the ciphertext. The ciphertext and public key in the scheme are of constant size. In addition, this new scheme offers public verification of the ciphertext. This property is very important to the large-scale group communication since the gateway can filter the incorrect ciphertext and alleviate the receiver's workload. Finally, a proof in the random oracle model is given to show that the scheme is secure against chosen ciphertext attack and existential forgery. 相似文献
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签密能高效地同时完成数据加密与认证,可用于设计紧凑的安全通信协议.签密中的仲裁机制用于保护签密的不可抵赖性,但同时用于仲裁的信息可能危及协议安全.本文指出签密仲裁中存在仲裁者解密攻击和仲裁机制无法保护明文完整性两种安全隐患,归纳其原因并指出解决方法.提出一个可安全仲裁的安全混合签密方案SASC,并在随机预言机模型下证明SASC方案具有IND-CCA2和UF-CMA安全性;SASC基于明文仲裁,不仅能维护明完整性而且能抵抗仲裁者解密攻击.SASC方案不增加计算量和通信量,且对明文的长度没有限制. 相似文献