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针对现有的格上身份基线性同态签名方案密钥存储量大、结构复杂导致方案实际运行效率相对偏低的问题,提出了一个NTRU(Number Theory Research Unit)格上高效的身份基线性同态签名方案。首先在密钥生成阶段利用NTRU密钥生成算法产生主密钥,接着采用格基委派算法给出身份签名私钥,最后运行NTRU格上原像抽样算法产生出线性同态签名。对方案的安全性证明与性能分析结果表明,新方案满足正确性,具有弱内容隐私性。在随机预言机模型下,该方案在小整数解问题困难性条件下满足适应性选择身份和选择消息的存在性不可伪造性。同时,由于采用NTRU格的特殊结构,新方案在密钥量与运行效率方面与已有方案相比较均具有显著的优势,这对于计算资源受限环境的同态认证中具有重要的应用价值。 相似文献
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已有的基于格的密文策略属性基(CP-ABE)方案只能通过矩阵运算方法进行加解密,加解密效率不高,而效率较高的基于理想格的密钥策略属性基(KP-ABE)方案又存在对各类实际应用场景适应性较差的问题。为解决上述问题,该文利用理想格上的算法生成主密钥和密钥,同时在多项式环上进行运算,极大地提高了加解密效率;通过在原属性集合中添加虚拟属性,方案成功结合访问结构生成密文,同时授权用户可以构建出满足解密条件的子集,从而实现方案的正确解密;还利用单个陷门矩阵生成密钥,有效降低了公共参数和主密钥的数量。最终该文构建了一个基于理想格的支持门限访问结构的高效CP-ABE方案,并证明方案在环上容错学习(R-LWE)假设下是选择性安全的。与现有支持门限访问结构的方案的对比分析表明,该文方案公共参数数量更少、效率更高,且对实际应用场景有更好的适应性。 相似文献
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广义签密可以灵活地工作在签密、签名和加密三种模式,具有很强的实用性.本文结合基于格的签名方案和密钥交换协议,构造了一个无陷门的广义签密方案.方案构造中引入了区分函数,根据输入的发送方与接收方密钥情况来自动识别加密、签名和签密三种模式,保障了算法在这三种工作模式下的优美对称性.基于环上判定性LWE问题,并借鉴FO13的方法,证明了该方案满足自适用抗选择密文攻击不可区分性安全性(IND-CCA2)和自适用抗选择消息攻击强不可伪造性安全性(SUF-CMA).该方案是基于Fiat-Shamir的中止(abort)框架,没有用到复杂的原像抽样和陷门生成算法,具有较高的计算效率. 相似文献
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针对现有可信中继QKD(Quantum Key Distribution)网络路由方案应用于广域环境时存在着密钥交换效率低、密钥资源无意义消耗大的问题,分析了影响密钥交换效率的因素,设计了适应广域QKD网络的分层路由方案.该方案将QKD网络划分为若干路由域,并通过拓扑聚合构建分层QKD网络,设计了基于最低层网络匹配的跨域密钥路由算法,使得高层路由域内一跳便可跨过多个低层路由域,极大地降低了密钥中继跳数,提高了密钥交换效率及密钥资源利用率.仿真结果表明分层路由方案相对于现有单层逐跳式路由方案能够提高大约77.6%密钥资源利用率,同时缩短一半密钥服务延时. 相似文献
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In the post quantum era, public key cryptographic scheme based on lattice is considered to be the most promising cryptosystem that can resist quantum computer attacks. However, there are still few efficient key agreement protocols based on lattice up to now. To solve this issue, an improved key agreement protocol with post quantum security is proposed. Firstly, by analyzing the Wess-Zumino model + ( WZM + ) key agreement protocol based on small integer solution (SIS) hard problem, it is found that there are fatal defects in the protocol that cannot resist man-in-the-middle attack. Then based on the bilateral inhomogeneous small integer solution (Bi-ISIS) problem, a mutual authenticated key agreement (AKA) protocol with key confirmation is proposed and designed. Compared with Diffie-Hellman (DH) protocol, WZM + key agreement protocol, and the AKA agreement based on the ideal lattice protocol, the improved protocol satisfies the provable security under the extend Canetti-Krawczyk (eCK) model and can resist man-in-the-middle attack, replay attack and quantum computing attack. 相似文献
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Key exchange protocols play an important role in securing the network communication over an insecure channel. In literature, a large number of key exchange schemes exist. The security of most of them is based on the Diffie‐Hellman (DH) problems over a group. But these types of DH problems are solvable in the presence of quantum computers. Thus, we require a non‐DH type key exchange scheme that resists to the quantum computers and new modern technologies. In this paper, 2 novel lattice‐based authenticated key exchange (LB‐AKE) protocols, (1) using a signature‐based authenticator and (2) using a signcryption‐based authenticator, are devised in Canetti‐Krawczyk proof model. The security of proposed protocols depends on the hardness of small integer solutions on the lattice. An extensive proof of security to our claim is given. The proposed AKEs characterize faster computation speed and resistance to the modern complex computers. 相似文献
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已有基于属性的认证密钥交换协议都是在单属性机构环境下设计的,而实际应用中不同属性机构下的用户也有安全通信的需求。该文在Waters属性基加密方案的基础上提出了一个多属性机构环境下的属性基认证密钥交换协议,并在基于属性的eCK(extended Canetti-Krawczyk)模型中将该协议的安全性归约到GBDH(Gap Bilinear Diffie-Hellman)和CDH(Computational Diffie-Hellman)假设,又通过布尔函数传输用线性秘密共享机制设计的属性认证策略,在制订灵活多样的认证策略的同时,显著地降低了通信开销。 相似文献
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群组签密既能实现群组签名,又能实现群组加密,但是现有的群组签密方案的发送者和接收者基本上在同一个密码系统中,不能满足现实环境的需求,而且基本上采用的是公钥加密技术,公钥加密技术在加密长消息时效率较低。因此该文提出由基于身份的密码体制(IBC)到无证书密码体制(CLC)的异构密码系统的混合群组签密方案。在该方案中,私钥生成器(PKG)和密钥生成中心(KGC)能够分别在IBC密码体制和CLC密码体制中产生自己的系统主密钥;而且群组成员只有协作才能解签密,提高了方案的安全性;同时在无需更换群组公钥和其他成员私钥的情况下,用户可以动态地加入该群组。所提方案采用了混合签密,具有可加密任意长消息的能力。在随机预言模型下,证明了该文方案在计算Diffie-hellman困难问题下具有保密性和不可伪造性。通过理论和数值实验分析表明该方案具有更高的效率和可行性。 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
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McEliece and Goldreich–Goldwasser–Halevi (GGH) cryptosystems are two instances of code and lattice-based cryptosystems whose security are based on the hardness of coding theoretic and lattice problems, respectively. However, such cryptosystems have a number of drawbacks which make them inefficient in practice. On the other hand, low density lattice codes (LDLCs) are practical lattice codes which can achieve capacity over additive white Gaussian noise channel and also can be encoded and decoded efficiently. This paper introduces a public key cryptosystem based on Latin square LDLCs, by which a relationship can be attained between code and lattice-based cryptography. In this way, we can exploit the efficient properties of codes and lattices, simultaneously to improve the security and efficiency of the proposed scheme. For instance, the security of this scheme is based on the hard problems related to lattices, i.e., closest vector problem and shortest basis problem, which in turn lead to increase the security level. On the other hand, we exploit the low complexity decoding algorithm of LDLCs to reduce the computational complexity. Moreover, this property allows using the larger values of the codeword length. Also, we use the special Gaussian vector, whose variance is upper bounded by Poltyrev bound, as the perturbation (error) vector. These strategies make the proposed scheme to be secure against the conventional cryptanalytic attacks. 相似文献