Cryptanalysis and improvement of an efficient authenticated key exchange protocol with tight security reduction

The SMEN protocol, proposed by Wu and Ustaoglu in 2009, has been considered to be secure as the authors claimed, and numerous theories are proposed based on this protocol. This paper analyzes the SMEN protocol and finds that this protocol is not resistant to the session corruption attack and the key compromise impersonation attack. Then, we propose an improved protocol with tight security reduction. Our improved protocol not only avoids the above attacks but also embraces the same efficiency as the SMEN protocol in terms of exponentiation. Besides, formal analysis of the improved protocol is presented by using the formal automatic security analysis tool Scyther. Copyright © 2014 John Wiley & Sons, Ltd.     

Improvement of McCullagh-Barreto key agreement with KCI-security

McCullagh-Barreto key agreement protocol and its variant achieve perfect forward security and key generation center (KGC) forward security, but provide no resistance to key compromise impersonation attack (KCI attack). In this paper, we give a formal treatment of key compromise impersonation (KCI) attack and define the security notion against it. Then an variant of McCullagh-Barreto protocol is presented with only one more Hash operation. The improved protocol preserves perfect forward security and KGC forward security, and furthermore is proved to be secure against KCI attack under k-Gap-BCAA1 assumption.     

Cryptanalysis of an efficient three‐party password‐based key exchange scheme

Three‐party password‐authenticated key exchange (3PAKE) protocols allow entities to negotiate a secret session key with the aid of a trusted server with whom they share a human‐memorable password. Recently, Lou and Huang proposed a simple 3PAKE protocol based on elliptic curve cryptography, which is claimed to be secure and to provide superior efficiency when compared with similar‐purpose solutions. In this paper, however, we show that the solution is vulnerable to key‐compromise impersonation and offline password guessing attacks from system insiders or outsiders, which indicates that the empirical approach used to evaluate the scheme's security is flawed. These results highlight the need of employing provable security approaches when designing and analyzing PAKE schemes. Copyright © 2011 John Wiley & Sons, Ltd.     

An efficient chaos‐based 2‐party key agreement protocol with provable security

Key agreement protocol is an important cryptographic primitive, which allows 2 parties to establish a secure session in an open network environment. A various of key agreement protocols were proposed. Nowadays, there still exists some other security flaws waiting to be solved. Owing to reduce the computational and communication costs and improve the security, chaotic map has been studied in‐depth and treated as a good solution. Recently, Liu et al proposed a chaos‐based 2‐party key agreement protocol and demonstrated that it can defend denial‐of‐service attack and replay attack. We found, however, it cannot resist off‐line password‐guessing attack, and it also has some other security flaws. In this paper, we propose an improved chaos‐based 2‐party key agreement protocol. The results prove that the protocol can solve the threats of off‐line password‐guessing attack and other security flaws in the security proof section. What is more, performance analysis shows that the computational cost of the improved protocol is lower than Liu et al protocol.     

传感器网络安全协议的分析和改进

分析A.Perrig提出的传感器网络安全协议套件的安全性,发现其中的节点密钥协商协议存在攻击,即攻击者可以冒充合法节点发送密钥协商请求。针对以上攻击,给出了一个改进协议。为了分析改进协议的安全性,对原始串空间理论进行了扩展,并使用扩展后的理论从保密性和认证性两个方面分析了改进协议的安全性。分析结果显示,改进后的协议是安全的。同时,对串空间理论的扩展,为其能够分析较复杂的安全协议打下了基础。     

Cryptanalysis and security enhancement of a robust two‐factor authentication and key agreement protocol

Two‐factor user authentication scheme allows a user to use a smart card and a password to achieve mutual authentication and establish a session key between a server and a user. In 2012, Chen et al. showed that the scheme of Sood et al. does not achieve mutual authentication and is vulnerable to off‐line password guessing and smart card stolen attacks. They also found that another scheme proposed by Song is vulnerable to similar off‐line password guessing and smart card stolen attacks. They further proposed an improved scheme. In this paper, we first show that the improved scheme of Chen et al. still suffers from off‐line password guessing and smart card stolen attacks, does not support perfect forward secrecy, and lacks the fairness of session key establishment. We then propose a new security‐enhanced scheme and show its security and authentication using the formal verification tool ProVerif, which is based on applied pi calculus. Copyright © 2014 John Wiley & Sons, Ltd.     

对Bellare-Rogaway 3PKD模型安全性定义的修正

指出Bellare和Rogaway在1995年提出的三方密钥分发模型——Bellare-Rogaway 3PKD模型的安全性定义存在缺陷。为此,设计了一个新的三方密钥分发协议P-Flaw。该协议在Bellare-Rogaway 3PKD模型下是可证明安全的。但是通过分析发现该协议不能够抵抗服务器欺骗攻击、已知会话密钥攻击和重放攻击等攻击形式,其原因在于Bellare-Rogaway 3PKD模型不能够对分发的会话密钥进行源识别。利用匹配会话的概念,修正了Bellare-Rogaway 3PKD模型的安全性定义。     

一种多方可认证密钥协商方案的分析与改进

在无证书公钥密码体制下对一种多方可认证密钥协商方案进行了分析,指出该方案无法抵抗合法用户的扮演攻击和口令偶尔泄露导致的危机。分析了该方案存在漏洞的原因,并在此基础上给出一个改进的密钥协商方案。新方案引入密钥种子和口令进化机制解决了上述问题,同时消除了冗余消息,降低了用户占用的带宽。分析表明新方案的安全性更强。     

网络支付协议的形式化安全需求及验证逻辑

从整个网络支付协议的安全角度出发，提出网络支付协议的多层安全需求模型，包括以认证和密钥分配为基础的基层需求、网络支付协议固有的中层需求(包括保密性、原子性、公平性、完整性、匿名性、不可否认性、可追究性等)、以及面向具体应用的高层需求。基于一阶逻辑和时序逻辑，提出一种适合描述网络支付协议的形式化安全需求的逻辑，描述了该逻辑的语法结构和推理规则，并用该安全需求逻辑对网络支付协议的多层安全需求进行了形式化描述。最后，以SET协议为例进行需求验证。     

Cryptanalysis and improvement of ‘a robust smart‐card‐based remote user password authentication scheme’

With the use of smart card in user authentication mechanisms, the concept of two‐factor authentication came into existence. This was a forward move towards more secure and reliable user authentication systems. It elevated the security level by requiring a user to possess something in addition to know something. In 2010, Sood et al. and Song independently examined a smart‐card‐based authentication scheme proposed by Xu et al. They showed that in the scheme of Xu et al., an internal user of the system can turn hostile to impersonate other users of the system. Both of them also proposed schemes to improve the scheme of Xu et al. Recently, Chen et al. identified some security problems in the improved schemes proposed by Sood et al. and Song. To fix these problems, Chen et al. presented another scheme, which they claimed to provide mutual authentication and withstand lost smart card attack. Undoubtedly, in their scheme, a user can also verify the legitimacy of server, but we find that the scheme fails to resist impersonation attacks and privileged insider attack. We also show that the scheme does not provide important features such as user anonymity, confidentiality to air messages, and revocation of lost/stolen smart card. Besides, the scheme defies the very purpose of two‐factor security. Furthermore, an attacker can guess a user's password from his or her lost/stolen smart card. To meet these challenges, we propose a user authentication method with user anonymity. We show through analysis and comparison that the proposed scheme exhibits enhanced efficiency in contrast to related schemes, including the scheme of Chen et al. Copyright © 2013 John Wiley & Sons, Ltd.     

Cryptanalysis and improvement of a three‐party password‐based authenticated key exchange protocol with user anonymity using extended chaotic maps

Three‐party password‐authenticated key exchange (3PAKE) protocols allow two clients to agree on a secret session key through a server via a public channel. 3PAKE protocols have been designed using different arithmetic aspects including chaotic maps. Recently, Lee et al. proposed a 3PAKE protocol using Chebyshev chaotic maps and claimed that their protocol has low computation and communication cost and can also resist against numerous attacks. However, this paper shows that in spite of the computation and communication efficiency of the Lee et al. protocol, it is not secure against the modification attack. To conquer this security weakness, we propose a simple countermeasure, which maintains the computation and communication efficiency of the Lee et al. protocol. Copyright © 2014 John Wiley & Sons, Ltd.