简单的三方口令密钥交换协议

基于口令认证的三方密钥交换协议（3PAKE）是通信双方在认证服务器的帮助下能在公开非安全的信道上协商并建立一个共享会话密钥。虽然目前有不少该方面的研究,但多数后来被证实易受攻击。本文给合以往的研究,提出一个不需服务器公钥体系的简单的基于口令认证的三方密钥交换协议。本文的协议不仅能抵抗各种攻击,而且计算成本和通信成本都比较低。     

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...     

基于不同口令认证的跨域组密钥协议

近年来关于基于口令认证的密钥交换协议(PAKE)进行了广泛的研究,基于口令认证的组密钥交换协议已成为安全协议研究的焦点问题.Byun等人也先后提出了基于不同口令认证的跨域环境下端到端的两个客户之间的PAKE(C2C-PAKE)密钥交换协议.然而在实际应用中,往往还需要在多个客户或客户组之间建立安全的通信信道.因此,提出了基于不同口令认证的跨域组间密钥交换协议,该协议将Zhiguo Wan等人所提出的nPAKE+协议扩展到了两个域,实现了两个域中的客户组在域服务器的协助下,建立域间共享的组会话密钥的过程,并给出了安全分析和执行效率的代价分析.     

改进的三方口令验证元认证密钥交换协议

在三方口令认证密钥交换（三方PAKE）协议中,每个用户仅仅需要和服务器共享一个口令,就可以在服务器的协助下与他人进行安全的密钥交换.由于有效地减少了用户管理口令的负担,三方PAKE协议在大规模用户集的安全通信中受到了较多关注.然而,已有的三方PAKE协议大多关注的是服务器利用明文存储用户口令的情形,没有考虑服务器口令文件泄露所造成的巨大威胁.在服务器端存放的是相应于用户口令的验证元的情形下,研究三方PAKE协议的分析和设计.首先分析了一个最近提出的基于验证元的三方PAKE协议,指出该协议易于遭受离线字典攻击,因此未能达到所宣称的安全性;其次,在分析已有协议设计缺陷的基础上,提出了一个新的基于验证元的三方PAKE协议,并在标准模型下证明了所设计的协议的安全性,与已有协议的比较表明,新提出的协议在提供了更高安全性的同时具有可接受的计算和通信效率.     

基于RLWE的双因子三方认证密钥交换协议

为了使格上Diffie-Hellman式密钥交换协议能够实现认证性并且适用于客户-服务器-客户模式的大规模通信,提出了一个基于环上误差学习RLWE的双因子三方认证密钥交换协议。该协议将口令和生物特征作为客户的长期密钥,实现服务器对客户的显式身份认证。首先利用环上误差学习的困难问题的优势（密钥及密文尺寸短、运行效率高）来构造密码体制;其次服务器通过口令和生物特征的哈希值传递环元素,并结合丁式错误协调机制使得通信方获得随机均匀的会话密钥。最后分析表明,该协议适用于大规模通信,提高了通信量,具有更高的安全属性,可以抵抗口令泄露用户假冒攻击。     

改进的三方口令认证密钥交换协议

基于三方的口令认证密钥交换（3PAKE）协议是客户通过与可信服务器共享一个口令验证元,在两客户进行通信时通过此可信服务器进行会话密钥的建立与共享,从而进行通信。首先对李文敏等人提出的协议进行安全性分析,发现该协议易受离线字典攻击和服务器泄露攻击。提出了一个改进协议,该协议能够提供双向认证、会话密钥机密性和前向安全性,能够有效抵抗多种攻击,包括离线字典攻击和服务器泄露攻击。     

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.     

新的基于椭圆曲线的三方口令认证密钥协商协议

口令认证密钥协商使得参与通信的用户用一个低熵的口令就可以实现实体认证,并能通过不安全的信道安全地生成共享的高熵会话密钥。为此,设计了一种新的基于椭圆曲线的三方口令认证密钥协商协议,新协议将参与者的口令巧妙地隐藏在传输的消息中,确保了口令的安全性。新协议的安全性基于椭圆曲线离散对数问题,服务器并不需要完全可信。安全性分析和性能分析显示,新协议以较低的代价实现了通信双方的安全通信。     

一种简单的口令基三方密钥交换协议

三方密钥交换协议是双方交换协议的推广,现存的大多数三方密钥交换协议都是用户—用户—服务器模式的,此类协议大多不能抵抗不可检测的口令猜测在线攻击。为此构造一个改进的口令基三方密钥交换协议。该改进协议较为复杂且两用户间需要3轮交换。为提高效率,基于CDH与DDH等基本的密码学假设,提出一个简单的口令基三方密钥交换协议。在AIP模型下证明该协议的安全性。     

基于椭圆曲线的加密密钥交换协议

加密密钥交换协议(EKE)的目的是利用安全性低的口令协商安全性高的密钥,进而利用密钥对以后的通信进行加密或身份认证,从而实现安全通信.基于验证元的EKE是针对服务器泄露攻击问题提出的.本文基于椭圆曲线密码系统的特点,给出了一个基于验证元的3EKE,该协议中,服务器通过口令实现对用户的认证;协议能够抵抗服务器泄露等攻击,...     

基于自验证公钥的跨域口令认证密钥协商协议

结合自验证公钥密码学和口令构造了一个用户可以直接通信的跨域口令认证密钥协商协议。域服务器通过口令认证实现对域内用户的认证, 并与对方域服务器一起协助用户完成认证和密钥协商。该过程中, 域服务器不能获取关于会话密钥的任何信息, 且各参与方之间能够实现相互认证。与同类协议相比, 该协议需要较小的计算和通信代价, 并能抵抗字典攻击和未知会话密钥共享攻击。     

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.     

Provably secure three-party password authenticated key exchange protocol in the standard model

Three-party password authenticated key exchange protocol is a very practical mechanism to establish secure session key through authenticating each other with the help of a trusted server. Most three-party password authenticated key exchange protocols only guarantee security in the random oracle model. However, a random oracle based cryptographic construction may be insecure when the oracle is replaced by real function. Moreover, some previous unknown attacks appear with the advance of the adversary capability. Therefore, a suitable standard model which can imitate a wider variety of attack scenarios for 3PAKE protocol is needed. Aim at resisting dictionary attack, unknown key-share attack and password-compromise impersonation attack, an expanded standard model for 3PAKE protocol is given. Meanwhile, through applying ElGamal encryption scheme and pseudorandom function, a specific three-party password authenticated key exchange protocol is proposed. The security of the proposed protocol is proven in the new standard model. The result shows that the present protocol has stronger security by comparing with other existing protocols, which covers the following security properties: (1) semantic security, (2) key privacy, (3) client-to-server authentication, (4) mutual authentication, (5) resistance to various known attacks, and (6) forward security.     

Security weakness in a three-party pairing-based protocol for password authenticated key exchange

Authentication and key exchange are fundamental for establishing secure communication channels over public insecure networks. Password-based protocols for authenticated key exchange are designed to work even when user authentication is done via the use of passwords drawn from a small known set of values. Recently, Wen et al. (H.-A. Wen, T.-F. Lee, T. Hwang, Provably secure three-party password-based authenticated key exchange protocol using Weil pairing, IEE Proceedings—Communications 152 (2) (2005) 138-143) proposed a new protocol for password-based authenticated key exchange in the three-party setting, where the clients trying to establish a common secret key do not share a password between themselves but only with a trusted server. Wen et al.’s protocol carries a claimed proof of security in a formal model of communication and adversarial capabilities. However, this work shows that the protocol for three-party key exchange is completely insecure and the claim of provable security is seriously incorrect. We conduct a detailed analysis of flaws in the protocol and its security proof, in the hope that no similar mistakes are made in the future.     

Design of a password-based authenticated key exchange protocol for SIP

The Session Initiation Protocol (SIP) is a signaling communications protocol, which has been chosen for controlling multimedia communication in 3G mobile networks. In recent years, password-based authenticated key exchange protocols are designed to provide strong authentication for SIP. In this paper, we address this problem in two-party setting where the user and server try to authenticate each other, and establish a session key using a shared password. We aim to propose a secure and anonymous authenticated key exchange protocol, which can achieve security and privacy goal without increasing computation and communication overhead. Through the analysis, we show that the proposed protocol is secure, and has computational and computational overheads comparable to related authentication protocols for SIP using elliptic curve cryptography. The proposed protocol is also provably secure in the random oracle model.     

基于混沌映射的用户匿名三方口令认证密钥协商协议

在基于混沌的三方口令认证密钥协商协议中,用户通过低熵的口令实现相互认证和共享会话密钥,以避免在身份认证过程中公钥基础设施或存储用户长期密钥的安全威胁。通过分析Lee提出的基于混沌映射的口令认证密钥协商协议,发现其协议不能进行口令变更,而且仅适用于用户和服务器之间的两方通信。为了改进此方案,提出两个基于切比雪夫混沌映射的用户匿名三方口令认证密钥协商协议,包括基于时钟同步的密钥协商方案和基于随机数的密钥协商方案。其中基于时钟同步的用户匿名三方口令认证密钥协商协议通信量少,基于随机数的用户匿名三方口令认证密钥协商协议更容易实现。两个方案的优点是用户仅选择一个简单的口令进行相互认证和密钥协商,服务器不需要再保护用户口令表,避免了口令相关的攻击,而且在相互认证过程中用户使用临时身份和哈希函数,实现用户匿名性,在增强协议安全性的同时,减少了通信过程中消息的数量,提高了协议的执行效率,具有完美前向安全,并用BAN逻辑证明了其安全性。     

A round- and computation-efficient three-party authenticated key exchange protocol

In three-party authenticated key exchange protocols, each client shares a secret only with a trusted server with assists in generating a session key used for securely sending messages between two communication clients. Compared with two-party authenticated key exchange protocols where each pair of parties must share a secret with each other, a three-party protocol does not cause any key management problem for the parties. In the literature, mainly there exist three issues in three-party authenticated key exchange protocols are discussed that need to be further improved: (1) to reduce latency, communication steps in the protocol should be as parallel as possible; (2) as the existence of a security-sensitive table on the server side may cause the server to become compromised, the table should be removed; (3) resources required for computation should be as few as possible to avoid the protocol to become an efficiency bottleneck. In various applications over networks, a quick response is required especially by light-weight clients in the mobile e-commerce. In this paper, a round- and computation-efficient three-party authenticated key exchange protocol is proposed which fulfils all of the above mentioned requirements.     

基于ECDSA的三方口令认证密钥交换协议

提出一种基于椭圆曲线数字签名算法(ECDSA)的三方口令认证密钥交换协议。将ECDSA分为公钥生成、签名过程和验证过程 3个阶段,在此基础上,设计协议过程、双向认证机制,使任意2个用户通过服务器能进行身份认证和密钥交换。分析结果表明,该协议能降低计算难度和存储开销,抵抗字典攻击和服务器泄露攻击。     

Secure verifier-based three-party password-authenticated key exchange

In order to secure large-scale peer-to-peer communication system, Chien recently presented a three-party password authenticated key exchange protocol using verifiers to reduce the damages of server corruption. In this paper, we first show his protocol is still vulnerable to a partition attack (offline dictionary attack). Thereafter we propose an enhanced verifier-based protocol that can defeat the attacks described and yet is reasonably efficient. Furthermore, we can provide the rigorous proof of the security for it.