基于RSA的网关口令认证密钥交换协议

网关口令认证密钥交换协议是一个三方协议,使得用户和网关在服务器的协助下建立起一个安全的会话密钥,从而实现用户和网关之间的安全通信.已有的网关口令认证密钥交换协议都是基于Diffie-Hellman密钥交换设计的.利用张木想所设计的PEKEP协议,提出了基于RSA体制的可证明安全的网关口令认证密钥交换协议.在随机预言模型...     

标准模型下高效的三方口令认证密钥交换协议

三方口令认证密钥交换协议允许两个分别与服务器共享不同口令的用户在服务器的协助下建立共享的会话密钥,从而实现了用户间端到端的安全通信.现阶段,多数的三方口令认证密钥交换协议都是在随机预言模型下可证明安全的.但在实际应用中,利用哈希函数对随机预言函数进行实例化的时候会给随机预言模型下可证明安全的协议带来安全隐患,甚至将导致协议不安全.以基于ElGamal加密的平滑投射哈希函数为工具,在共同参考串模型下设计了一种高效的三方口令认证密钥交换协议,并且在标准模型下基于DDH假设证明了协议的安全性.与已有的同类协议相比,该协议在同等的安全假设下具有更高的计算效率和通信效率,因此更适用于大规模的端到端通信环境.     

标准模型下隐私保护的多因素密钥交换协议

多因素认证密钥交换协议融合多种不同的认证因素来实现强安全的身份认证和访问控制,在具有高级别安全应用需求的移动泛在服务中具有巨大的应用潜力.现阶段多因素协议的研究成果还不丰富,并且已有协议都是在随机预言模型下可证明安全的.以两方口令认证密钥交换协议、鲁棒的模糊提取器以及签名方案为基本组件提出了一个标准模型下可证明安全的多因素协议.本文的协议中服务器不知道用户的生物模板,因此实现了对生物信息的隐私保护.与已有的随机预言模型下的多因素协议相比,本文的协议在满足更高安全性的同时具有更高的计算效率和通信效率,因此更满足高级别安全的移动泛在服务的应用需求.     

对两个口令认证密钥交换协议的安全性分析

口令认证密钥交换协议使得仅共享低熵口令的用户可以通过不安全的信道安全地协商出高熵的会话密钥,由于实用性较强受到了密码学研究者的广泛关注。对最近在“标准模型下高效的基于口令认证密钥协商协议”一文中提出的协议以及在“基于验证元的三方口令认证密钥交换协议”一文中提出的协议进行了分析,指出这两个口令认证密钥交换协议都是不安全的,难于抵抗离线字典攻击,进一步分析了原协议设计或安全性证明中被疏忽之处。     

改进的基于口令的三方密钥交换协议

通过对现有的一个三方密钥交换协议进行安全性分析,指出其存在的安全隐患,并以此为基础提出一个具有完善双向认证机制的三方密钥交换协议。该协议基于计算性Diffie-Hellman问题的难解性,只需三轮就能使通信双方协商好会话密钥,与现有的大多数协议相比具有较高的计算效率,并通过安全性分析证明它是安全的。     

有效的口令认证的三方密钥交换协议

对于口令认证的密钥交换协议的安全性要求,提出一种口令认证的三方密钥交换协议,利用服务器存储客户端口令的验证值、双线性对与基于身份加密算法等内容进行协议的设计,并对协议进行了安全性和效率的两个方面的分析。分析表明,所提出的协议具有口令认证的三方密钥交换协议的安全属性要求,也具有较好的效率。     

基于扩展Canetti-Krawczyk模型的认证密钥交换协议的模块化设计与分析

提出一种模块化的扩展Canetti-Krawczyk模型(简称meCK模型)以摆脱认证密钥交换协议对随机预言机的依赖.首先将认证密钥交换协议划分为秘密交换模块和密钥派生模块,并分别形式化定义其攻击者的能力与安全属性;然后综合上述模块得到认证密钥交换协议的模块化安全模型,并证明所提出的安全定义蕴涵原始的扩展Canetti-Krawczyk安全.借助协议模块化分析的思想,设计了一种高效且在标准模型下可证明安全的认证密钥交换协议(简称UPS协议).在meCK模型下,UPS协议的安全性可有效归约到伪随机函数簇、目标抗碰撞Hash函数簇和GapDiffie-Hellman等标准密码学假设上.与其他标准模型下可证明安全的协议相比,UPS协议所需的密码学假设更弱、更标准,且指数运算次数降低了50%～67%.最后,UPS协议的构造与安全性验证了所提出的模块化方法的合理性和有效性,并解决了ProvSec09上的一个公开问题.     

一种基于身份的三方认证密钥交换协议

为了确保公共网络环境的安全通信,一种三方认证密钥交换协议得到了广泛关注。2009年,Yang等提出了一个基于椭圆曲线密码的移动电子商务环境下的有效的三方认证密钥交换协议,然而Tan指出Yang等的协议会遭受假冒攻击,1h随后提出了一种改进协议。但是,Nose指出Tm的协议不能抵抗假冒攻击和中间人攻击。为了提高安全性,作者提出了一个新的三方认证密钥交换协议。     

一个前向安全的基于口令认证的三方密钥交换协议

目前,文献中提出的基于口令认证的密钥交换协议,很多都是针对两方的情形设计的,即通信双方为客户与服务器,它们通过一个预先共享的口令来进行认证的密钥交换.随着现代通信环境的快速变化,需要能为任意客户间构建一个端到端的安全信道,这种应用的情形与那些文献中所考虑的有很大区别.针对这种情形,文中提出了一个可证前向安全的基于口令认证的三方密钥交换协议,使通信双方在认证服务器的帮助下能相互进行认证并建立一个会话密钥.与前人提出的基于口令认证的三方密钥交换协议相比,该协议在计算代价和通信代价上都较有效,因而更适用于资源受限的环境.此协议的安全性是在口令型的选择基Gap Diffie-Hellman问题难解的假设前提下在随机谕示模型下证明的.     

基于口令的三方认证密钥交换协议

传统的三方认证密钥交换协议不具备前向安全性,难以抵抗不可察觉在线字典攻击。为此,研究简单三方口令认证密钥交换协议,分析其存在的安全漏洞并加以改进,提出一种基于口令的三方认证密钥交换协议。分析结果表明,与其他协议相比,该协议的执行效率和安全性较高。     

Provably secure authenticated key exchange protocol under the CDH assumption

Constructing a secure key exchange protocol is one of the most challenging problems in information security. We propose a provably secure two-round two-party authenticated key exchange (2AKE) protocol based on the well-studied CDH assumption in eCK model to provide the strongest definition of security for key exchange protocol when using the matching session to define the partnership. The underlying hardness assumption (CDH assumption) of our protocol is weaker than these of four other provably secure 2AKE protocols in CK model or eCK model and the computational cost of our protocol is reasonable. We also present a three-round variant of our protocol to realize key conformation.     

Strongly secure identity-based authenticated key agreement protocols

In this paper, we present a strongly secure identity-based (ID-based) two-party authenticated key agreement (AKA) protocol, which captures all basic desirable security properties including master key forward secrecy, ephemeral secrets reveal resistance and so on, and is provably secure in the extended Canetti-Krawczyk (eCK) model. The security of the protocol can be reduced to the standard Computational Bilinear Diffie-Hellman assumption in the random oracle model. Our scheme is secure as long as each party has at least one uncompromised secret. Also, we give a strongly secure variant of the protocol. The variant has a much lower computational overhead than the original scheme, while its security relies on the Gap Bilinear Diffie-Hellman assumption. Currently, there are few ID-based AKA protocols that are provably secure in the strong eCK model. Compared with previous ID-based AKA schemes, our protocols have advantages over them in security or efficiency.     

ASICS: authenticated key exchange security incorporating certification systems

Most security models for authenticated key exchange (AKE) do not explicitly model the associated certification system, which includes the certification authority and its behaviour. However, there are several well-known and realistic attacks on AKE protocols which exploit various forms of malicious key registration and which therefore lie outside the scope of these models. We provide the first systematic analysis of AKE security incorporating certification systems. We define a family of security models that, in addition to allowing different sets of standard AKE adversary queries, also permit the adversary to register arbitrary bitstrings as keys. For this model family, we prove generic results that enable the design and verification of protocols that achieve security even if some keys have been produced maliciously. Our approach is applicable to a wide range of models and protocols; as a concrete illustration of its power, we apply it to the CMQV protocol in the natural strengthening of the eCK model to the ASICS setting.     

强安全高效的认证密钥交换协议

提出一个认证密钥交换协议AKE-1。与已有的协议相比,AKE-1效率较高。基于随机预言假设和CDH假设,该协议被证明在eCK07模型下是安全的。AKE-1使用的技术是Cash, Kiltz和Shoup最近提出的陷门测试。基于AKE-1给出一轮的变体(满足只有一个实体在线)和三轮的变体(提供密钥确认属性)以满足不同的应用。     

强安全高效的认证密钥交换协议

提出一个认证密钥交换协议AKE-1。与已有的协议相比,AKE-1效率较高。基于随机预言假设和CDH假设,该协议被证明在eCK07模型下是安全的。AKE-1使用的技术是Cash, Kiltz和Shoup最近提出的陷门测试。基于AKE-1给出一轮的变体(满足只有一个实体在线)和三轮的变体(提供密钥确认属性)以满足不同的应用。     

Escrowable identity-based authenticated key agreement protocol with strong security

Escrowable identity-based authenticated key agreement protocols are welcome in certain closed groups applications, where audit trail is a legal requirement. In this paper, we present a strongly secure one-round escrowable identity-based two-party authenticated key agreement protocol, which captures all basic desirable security properties including perfect forward secrecy, ephemeral secrets reveal resistance and so on, and is provably secure in the extended Canetti–Krawczyk (eCK) model. We show that the security of the protocol can be reduced to the standard computational bilinear Diffie–Hellman assumption in the random oracle model. Assuming that no adversary can obtain the master private key for the escrow mode, our scheme is secure as long as each party has at least one uncompromised secret. To the best of our knowledge, our scheme is the first escrowable identity-based authenticated key agreement protocol provably secure in the eCK model.     

高效的强安全的基于身份认证密钥协商协议

现有的基于身份(ID)认证协议大多在CK模型中被证明是安全的,而CK模型比扩展的CK模型(eCK模型)更弱。基于NAXOS方法,利用双线性对设计了一种新协议,并基于随机预言假设和GBDH假设,在eCK模型中证明了协议的安全性。与其他的基于身份认证协议相比,新协议的计算复杂度和通信复杂度较低;满足主密钥前向安全性和完美前向安全性,并抗密钥泄漏伪装。     

A strongly secure pairing-free certificateless authenticated key agreement protocol under the CDH assumption基于CDH假设的强安全的无对的无证书认证密钥协商协议

Certificateless authenticated key agreement (CL-AKA) protocols have been studied a great deal since they neither suffer from a heavy certificate management burden nor have the key escrow problem. Recently, many efficient CL-AKA protocols without pairings have been built. However, these pairing-free CL-AKA protocols are either not proved in any formal security model or proved under the gap Diffie-Hellman (GDH) assumption, a non-standard and strong assumption. With available implementation technologies, pairings are needed to realize the GDH assumption, which means that these pairing-free CL-AKA protocols are not pure pairing-free. Furthermore, these protocols are insecure in the strengthened eCK (seCK) model, which encompasses the eCK model and considers leakages on intermediate results. In this paper, we present a pure pairing-free CL-AKA protocol, which is provably secure in the seCK model under the standard computational Diffie-Hellman (CDH) assumption. Compared with the existing CL-AKA protocols, the proposed protocol has advantage over them in security or efficiency.     

一种基于TTP的两方认证密钥交换协议

本文提出了一种适合大规模C2C通信环境的两方密钥交换TTP-TPAKE协议,协议中的每个通信实体和可信中心共享一个可记忆的口令,然后在该可信第三方的帮助下,每对通信实体生成他们的会话密钥。该协议只需四轮通信,不需棘手的公钥基础设施作为支撑,具有较高的计算和通信效率。在随机预言模型和理想密文系统下,形式化地证明了TTP-TPAKE协议具备AKE安全。