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...     

标准模型下网关口令认证密钥交换协议的通用框架

网关口令认证密钥交换协议允许用户和网关在服务器的协助下建立起一个共享的会话密钥.网关口令协议适用于无线通信环境,如GSM和3GPP等.已有的网关口令认证密钥交换协议大多缺乏严格的安全证明,或者是在随机预言模型下证明安全的.该文采用模块化的设计方法提出了在标准模型下构造网关口令协议的通用框架.通用框架可以实现双向认证并且能够抵抗不可检测在线字典攻击,因此具有更强的安全性.利用DDH假设、二次剩余假设和N次剩余假设对通用框架进行实例化可以得到不同的标准模型下可证明安全的网关口令协议.     

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.     

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。     

运用DH-EKE增强WTLS握手协议的安全性

WTLS握手协议不满足前向安全性,非匿名验证模式下不满足用户匿名性,完全匿名模式下易遭受中间人攻击.DH-EKE协议具有认证的密钥协商功能,将改进的DH-EKE集成到WTLS握手协议中,只需使用可记忆的用户口令,不需使用鉴权证书及数字签名.该方案适用于完全匿名的验证模式,可抵御中间人攻击和字典式攻击,且在服务器中不直接存储口令,攻击者即使攻破服务器获得口令文件也无法冒充用户,能够在WTLS握手协议中实现简单身份认证和安全密钥交换.     

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.     

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。     

面向智能家居的轻量型互认证协议

针对现有智能家居远程控制互认证协议不能兼顾效率与安全性的现状,提出一个面向智能家居的轻量型互认证协议,实现用户、网关与测控节点间的相互认证及密钥协商.协议基于USBkey和用户口令,采用挑战/应答机制,仅利用伪随机数及异或与哈希运算;在认证与协商阶段,通过单向哈希当前会话密钥获得可变共享密钥参与下一次认证,实现认证协议的一次一密,这种方法有助于提高协议的安全性及运行效率.最后,对比分析结果表明:本文协议有更高的安全性,且通过降低网关和节点的计算量、通信量及能源消耗,避免无线传感网的时间戳机制,实现了轻量型目标.     

一种适合远程访问场景的认证和密钥交换方案

提出了一种基于基本ECMQV协议的非对称式认证和密钥交换方案AEAS，可实现对客户端的口令认证和对服务端的公钥认证；AEAS中的客户端口令认证具有零知识安拿属性，允许用户使用弱口令，并能抵御各种字典攻击和重放攻击；与同类非对称认证和密钥交换方案相比，AEAS具有最少的公钥计算开销。AEAS协议能集成到现有WTLS协议框架中，从而实现一种高安全性和低计算开销的WTLS扩展，它完全可满足无线终端在企业远程访问场景下的高安全性要求。     

基于移动端协助的硬口令认证密钥交换协议

针对现有口令认证密钥交换协议易受各种网络攻击,影响用户私密信息安全的问题,提出一种基于移动端协助的硬口令认证密钥交换协议,在移动端的辅助下,允许用户使用单一口令建立与服务器之间的安全会话。协议中,用户无须记忆任何复杂的私钥信息,即使移动设备丢失、被盗或遭受恶意软件侵袭,也不会损害用户信息。安全性和性能分析表明,协议明显降低了服务器的计算消耗,大大提高了用户私密信息的安全性,可以抵御字典攻击、中间人攻击等的影响,减轻用户记忆负担,缓解存储压力,易于部署。     

An efficient and practical threshold gateway-oriented password-authenticated key exchange protocol in the standard model

With the assistance of an authentication server, a gateway-oriented password-authenticated key exchange (GPAKE) protocol can establish a common session key shared between a client and a gateway. Unfortunately, a GPAKE protocol becomes totally insecure if an adversary can compromise the authentication server and steal the passwords of the clients. In order to provide resilience against adversaries who can hack into the authentication server, we propose a threshold GPAKE protocol and then present its security proof in the standard model based on the hardness of the decisional Diffie-Hellman (DDH) problem. In our proposal, the password is shared among n authentication servers and is secure unless the adversary corrupts more than t+1 servers. Our protocol requires n > 3t servers to work. Compared with existing threshold PAKE protocols, our protocol maintains both stronger security and greater efficiency.     

An efficient user authentication and key exchange protocol for mobile client–server environment

Considering the low-power computing capability of mobile devices, the security scheme design is a nontrivial challenge. The identity (ID)-based public-key system with bilinear pairings defined on elliptic curves offers a flexible approach to achieve simplifying the certificate management. In the past, many user authentication schemes with bilinear pairings have been proposed. In 2009, Goriparthi et al. also proposed a new user authentication scheme for mobile client–server environment. However, these schemes do not provide mutual authentication and key exchange between the client and the server that are necessary for mobile wireless networks. In this paper, we present a new user authentication and key exchange protocol using bilinear pairings for mobile client–server environment. As compared with the recently proposed pairing-based user authentication schemes, our protocol provides both mutual authentication and key exchange. Performance analysis is made to show that our presented protocol is well suited for mobile client–server environment. Security analysis is given to demonstrate that our proposed protocol is provably secure against previous attacks.     

A lightweight authentication and key agreement protocol preserving user anonymity

Nowadays with widespread employment of the Internet, servers provide various services for legal users. The vital issue in client/server connections is authentication protocols that make the communication channel safe and secure against famous attacks. Recently, Kumari et al. and Chaudhry et al. proposed two authentication and key agreement protocols and illustrated that their proposed protocols are secure against various security attacks. However, in this paper we demonstrate that both protocols are vulnerable to off-line password guessing attacks. Moreover, we show that Kumari et al.’s protocol does not provide the property of user anonymity. In order to overcome these weaknesses, we propose a lightweight authentication and key agreement protocol. The correctness of the proposed protocol is proved using BAN logic. Security analysis demonstrates that the proposed protocol resists various security attacks and provides user anonymity. Furthermore, performance analysis confirms that the computation cost of the proposed protocol is acceptable.

     

Simple password-based three-party authenticated key exchange without server public keys

Password-based three-party authenticated key exchange protocols are extremely important to secure communications and are now extensively adopted in network communications. These protocols allow users to communicate securely over public networks simply by using easy-to-remember passwords. In considering authentication between a server and user, this study categorizes password-based three-party authenticated key exchange protocols into explicit server authentication and implicit server authentication. The former must achieve mutual authentication between a server and users while executing the protocol, while the latter only achieves authentication among users. This study presents two novel, simple and efficient three-party authenticated key exchange protocols. One protocol provides explicit server authentication, and the other provides implicit server authentication. The proposed protocols do not require server public keys. Additionally, both protocols have proven secure in the random oracle model. Compared with existing protocols, the proposed protocols are more efficient and provide greater security.     

An efficient and security dynamic identity based authentication protocol for multi-server architecture using smart cards

Generally, if a user wants to use numerous different network services, he/she must register himself/herself to every service providing server. It is extremely hard for users to remember these different identities and passwords. In order to resolve this problem, various multi-server authentication protocols have been proposed. Recently, Sood et al. analyzed Hsiang and Shih's multi-server authentication protocol and proposed an improved dynamic identity based authentication protocol for multi-server architecture. They claimed that their protocol provides user's anonymity, mutual authentication, the session key agreement and can resist several kinds of attacks. However, through careful analysis, we find that Sood et al.'s protocol is still vulnerable to leak-of-verifier attack, stolen smart card attack and impersonation attack. Besides, since there is no way for the control server CS to know the real identity of the user, the authentication and session key agreement phase of Sood et al.'s protocol is incorrect. We propose an efficient and security dynamic identity based authentication protocol for multi-server architecture that removes the aforementioned weaknesses. The proposed protocol is extremely suitable for use in distributed multi-server architecture since it provides user's anonymity, mutual authentication, efficient, and security.     

Remote user authentication and key agreement for mobile client–server environments on elliptic curve cryptography

In recent years, with the rapid advance of wireless mobile networks, secure and efficient authentication mechanisms that can operate over insecure wireless channels have become increasingly essential. To improve the efficiency in the energy-limited mobile devices, many authentication schemes using elliptic curve cryptography (ECC) have been presented. However, these schemes are still inefficient in terms of computation cost and communication overhead. Moreover, they suffer from various attacks, making them impractical due to their inherent design. To address their weaknesses, we propose a more efficient ID-based authentication scheme on ECC for mobile client–server environments with considering security requirements. The proposed scheme not only provides mutual authentication but also achieves session key agreement between the client and the server. Through a rigorous formal security proof under random oracle model, it has been indicated that the proposed protocol is secure against security threats. The informal security analysis shows that our scheme can resist well-known attacks and provides user anonymity. Performance analysis and comparison results demonstrate that our scheme outperforms the related competitive works and is more suitable for practical application in mobile client–server environments.     

一种无线切换认证协议的性能改进*

切换认证协议是确保移动节点在无线网络中多个接入点之间进行快速安全切换的关键。在设计切换认证协议时,必须充分考虑移动节点计算、存储能力低以及电池容量小等特点。针对无线局域网的切换认证协议HashHand双线性对运算消耗资源大的缺陷,提出了一种新的快速切换认证协议。该协议不使用对运算,仅使用加法群的点乘运算替代,提高了协议的效率。并且具有用户匿名性与不可追踪性,有条件的隐私保护性。用户与认证服务器满足互认证性,能够安全地协商会话密钥并且周期性地更新。该协议能有效地抵制重放攻击和拒绝服务攻击。     

Provably secure and efficient identification and key agreement protocol with user anonymity

Many authentication and key agreement protocols were proposed for protecting communicated messages. In previous protocols, if the user?s identity is transmitted in plaintext, an adversary can tap the communications and employ it to launch some attacks. In most protocols with user anonymity, they focus on satisfaction of several security requirements. From a client?s point of view, those protocols are not admired since the cost of storage, computation and communication is high. In pervasive computing, a client usually uses a limited-resource device to access multiple servers. The storage and computation are very important issues especially in this kind of environments. Also, for a convenience of designing protocol, most protocols use timestamps to prevent the replay attack. As we know, the serious time synchronization problem exists in timestamp-based protocols. Finally, most protocols do not have formal proofs for the security. In this paper, we propose a secure and efficient identification and key agreement protocol with user anonymity based on the difficulty of cracking the elliptic curve Diffie–Hellman assumption. In addition, we also propose an augmented protocol for providing the explicit mutual authentication. Compared with the related protocols, the proposed protocols? computation cost is lower and the key length is shorter. Therefore, our protocols are suitable even for applications in low power computing environments. Finally, we formally prove the security of the proposed protocols by employing the random oracle model.