On the security of a dynamic identity‐based remote user authentication scheme with verifiable password update

Recently, Chang et al. [Chang Y, Tai W, Chang H. Untraceable dynamic identity‐based remote user authentication scheme with verifiable password update. International Journal of Communication Systems 2013; doi:10.1002/dac.2552] proposed a dynamic identity‐based remote user authentication scheme with verifiable password update. They also proved that their scheme could withstand various attacks. Unfortunately, by proposing concrete attacks, we show that their scheme is vulnerable to three kinds of attacks. We also point out that their scheme cannot provide untraceability. The analysis shows that the scheme of Chang et al. is not suitable for practical applications. Copyright © 2013 John Wiley & Sons, Ltd.     

Cryptanalysis of a dynamic ID‐based remote user authentication with key agreement scheme

A dynamic user authentication scheme allows a user and a remote server to authenticate each other without leaking the user's identity. In 2011, Wen and Li proposed an improved dynamic ID‐based remote user authentication with key agreement scheme for mobile and home networks. They claimed that their scheme was more secure than the scheme of Wang et al. However, we demonstrate that their scheme is vulnerable to the privileged insider, off‐line password guessing, impersonation, and server spoofing attacks. At the same time, it does not provide any user anonymity and forward secrecy property. Thus, it is not feasible for real‐life implementation.Copyright © 2012 John Wiley & Sons, Ltd.     

Design and analysis of an improved smartcard‐based remote user password authentication scheme

With the fast development of the Internet and the telecommunication technologies, internet users are carrying out various electronic transactions over internet by means of the authentication protocols. To ensure efficient and robust online transaction, security of authentication protocol turns out to be a great concern nowadays. As a result, smartcard‐based password authentication and session key agreement scheme receives significant attention in recent years. In the literature, various authentication schemes have been proposed by the cryptographic research community. Recently, Li et al. analyze some security weaknesses of the authentication scheme of Chen et al. and propose an enhancement based on the discrete logarithm problem and computational Diffie–Hellman problem. This paper further cryptanalyzes the scheme of Li et al. and identifies various security loopholes and then constructs a modified authentication scheme as a remedy. The security and efficiency evaluations demonstrate that our scheme has more security features and low computation costs than the related schemes. Copyright © 2014 John Wiley & Sons, Ltd.     

Two‐factor authentication scheme using attribute and password

In this study, based on attribute and password, we introduce a new kind of two‐factor authentication protocol that has various applications such as anonymous authentication and privacy protection. Specifically, our proposal is constructed by introducing password authentication into the generic framework of attribute‐based authentication. Consequently, it not only achieves two‐factor authentication, but also enjoys the advantages of attribute authentication and password authentication simultaneously. Furthermore, to formally evaluate the security of the proposed protocol, we present the corresponding security model, within which the detailed security proof of the proposal is given. Copyright © 2014 John Wiley & Sons, Ltd.     

A robust and efficient dynamic identity‐based multi‐server authentication scheme using smart cards

In single‐server architecture, one service is maintained by one server. If a user wants to employ multiple services from different servers, he/she needs to register with these servers and to memorize numerous pairs of identities and passwords corresponding to each server. In order to improve user convenience, many authentication schemes have been provided for multi‐server environment with the property of single registration. In 2013, Li et al. provided an efficient multi‐server authentication scheme, which they contended that it could resist several attacks. Nevertheless, we find that their scheme is sensitive to the forgery attack and has a design flaw. This paper presents a more secure dynamic identity‐based multi‐server authentication scheme in order to solve the problem in the scheme by Li et al. Analyses show that the proposed scheme can preclude several attacks and support the revocation of anonymity to handle the malicious behavior of a legal user. Furthermore, our proposed scheme has a lower computation and communication costs, which make it is more suitable for practical applications. Copyright © 2014 John Wiley & Sons, Ltd.     

Cryptanalysis and security enhancement of a remote user authentication scheme using smart cards

With the broad implementations of the electronic business and government applications,robust system security and strong privacy protection have become essential requirements for remote user authentication schemes.Recently,Chen et al.pointed out that Wang et al.’s scheme is vulnerable to the user impersonation attack and parallel session attack,and proposed an enhanced version to overcome the identified security flaws.In this paper,however,we show that Chen et al.’s scheme still cannot achieve the claimed security goals and report its following problems:(1) It suffers from the offline password guessing attack,key compromise impersonation attack and known key attack;(2) It fails to provide forward secrecy;(3) It is not easily repairable.As our main contribution,a robust dynamic ID-based scheme based on non-tamper resistance assumption of the smart cards is presented to cope with the aforementioned defects,while preserving the merits of different related schemes.The analysis demonstrates that our scheme meets all the proposed criteria and eliminates several grave security threats that are difficult to be tackled at the same time in previous scholarship.     

Improvement of robust smart‐card‐based password authentication scheme

Smart‐card‐based password authentication scheme is one of the commonly used mechanisms to prevent unauthorized service and resource access and to remove the potential security threats over the insecure networks and has been investigated extensively in the last decade. Recently, Chen et al. proposed a smart‐card‐based password authentication scheme and claimed that the scheme can withstand offline password guessing attacks even if the information stored in the smart card is extracted by the adversary. However, we observe that the scheme of Chen et al. is insecure against offline password guessing attacks in this case. To remedy this security problem, we propose an improved authentication protocol, which inherits the merits of the scheme of Chen et al. and is free from the security flaw of their scheme. Compared with the previous schemes, our improved scheme provides more security guarantees while keeping efficiency. Copyright © 2013 John Wiley & Sons, Ltd.     

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 of an identity‐based authenticated key exchange protocol

Authenticated key exchange protocols represent an important cryptographic mechanism that enables several parties to communicate securely over an open network. Elashry, Mu, and Susilo proposed an identity‐based authenticated key exchange (IBAKE) protocol where different parties establish secure communication by means of their public identities.The authors also introduced a new security notion for IBAKE protocols called resiliency, that is, if the secret shared key is compromised, the entities can generate another shared secret key without establishing a new session between them. They then claimed that their IBAKE protocol satisfies this security notion. We analyze the security of their protocol and prove that it has a major security flaw, which renders it insecure against an impersonation attack. We also disprove the resiliency property of their scheme by proposing an attack where an adversary can compute any shared secret key if just one secret bit is leaked.     

Security flaws in two improved remote user authentication schemes using smart cards

Understanding security failures of cryptographic protocols is the key to both patching existing protocols and designing future schemes. In this paper, we analyze two recent proposals in the area of password‐based remote user authentication using smart cards. First, we point out that the scheme of Chen et al. cannot achieve all the claimed security goals and report its following flaws: (i) it is vulnerable to offline password guessing attack under their nontamper resistance assumption of the smart cards; and (ii) it fails to provide forward secrecy. Then, we analyze an efficient dynamic ID‐based scheme without public‐key operations introduced by Wen and Li in 2012. This proposal attempts to overcome many of the well‐known security and efficiency shortcomings of previous schemes and supports more functionalities than its counterparts. Nevertheless, Wen–Li's protocol is vulnerable to offline password guessing attack and denial of service attack, and fails to provide forward secrecy and to preserve user anonymity. Furthermore, with the security analysis of these two schemes and our previous protocol design experience, we put forward three general principles that are vital for designing secure smart‐card‐based password authentication schemes: (i) public‐key techniques are indispensable to resist against offline password guessing attack and to preserve user anonymity under the nontamper resistance assumption of the smart card; (ii) there is an unavoidable trade‐off when fulfilling the goals of local password update and resistance to smart card loss attack; and (iii) at least two exponentiation (respectively elliptic curve point multiplication) operations conducted on the server side are necessary for achieving forward secrecy. The cryptanalysis results discourage any practical use of the two investigated schemes and are important for security engineers to make their choices correctly, whereas the proposed three principles are valuable to protocol designers for advancing more robust schemes. Copyright © 2012 John Wiley & Sons, Ltd.     

Robust smart‐card‐based remote user password authentication scheme

Smart‐card‐based remote user password authentication schemes are commonly used for providing authorized users a secure method for remotely accessing resources over insecure networks. In 2009, Xu et al. proposed a smart‐card‐based password authentication scheme. They claimed their scheme can withstand attacks when the information stored on the smart card is disclosed. Recently, Sood et al. and Song discovered that the smart‐card‐based password authentication scheme of Xu et al. is vulnerable to impersonation and internal attacks. They then proposed their respective improved schemes. However, we found that there are still flaws in their schemes: the scheme of Sood et al. does not achieve mutual authentication and the secret key in the login phase of Song's scheme is permanent and thus vulnerable to stolen‐smart‐card and off‐line guessing attacks. In this paper, we will propose an improved and efficient smart‐card‐based password authentication and key agreement scheme. According to our analysis, the proposed scheme not only maintains the original secret requirement but also achieves mutual authentication and withstands the stolen‐smart‐card attack. Copyright © 2012 John Wiley & Sons, Ltd.     

A secure and enhanced elliptic curve cryptography‐based dynamic authentication scheme using smart card

In remote system security, 2‐factor authentication is one of the security approaches and provides fundamental protection to the system. Recently, numerous 2‐factor authentication schemes are proposed. In 2014, Troung et al proposed an enhanced dynamic authentication scheme using smart card mainly to provide anonymity, secure mutual authentication, and session key security. By the analysis of Troung et al's scheme, we observed that Troung et al' s scheme does not provide user anonymity, perfect forward secrecy, server's secret key security and does not allow the user to choose his/her password. We also identified that Troung et al's scheme is vulnerable to replay attack. To fix these security weaknesses, a robust authentication scheme is proposed and analyzed using the formal verification tool for measuring the robustness. From the observation of computational efficiency of the proposed scheme, we conclude that the scheme is more secure and easy to implement practically.     

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 improved remote password authentication scheme with smart card

This paper analyzes the security performance of a latest proposed remote two-factor user authentication scheme and proposes an improved scheme based on the dynamic ID to avoid the attacks it suffers. Besides this, in our proposed scheme the password is no longer involved in the calculation of verification phase which makes our scheme more secure and costs less than the old one. At last we analyze the performance of our proposed scheme to prove it provides mutual authentication between the user and the server. Moreover, it also resists password guessing attack, server and user masquerade attack and replay attack effectively.     

Cryptanalysis of flexible remote password authentication scheme of ICN'01

The weakness of Woei-Jiunn Tsaur's (see ICN 2001, p.174-83, 2001) flexible user authentication scheme for multi-server Internet services is demonstrated. We show that Tsaur's authentication scheme is vulnerable to the off-line guessing attack, i.e. we show that the user's additional two secret keys do not strengthen the security of Tsaur's scheme.     

一种基于平方剩余的动态口令算法

由于传统的静态口令认证方式在现在的网络环境里面临很多安全挑战，于是动态口令的概念被业内人士提出，本文提出了一种基于求解平方剩余的困难性而设计的动态口令的算法的思想。     

Cryptanalysis of Hsiang‐Shih's authentication scheme for multi‐server architecture

From user point of view, password‐based remote user authentication technique is one of the most convenient and easy‐to‐use mechanisms to provide necessary security on system access. As the number of computer crimes in modern cyberspace has increased dramatically, the robustness of password‐based authentication schemes has been investigated by industries and organizations in recent years. In this paper, a well‐designed password‐based authentication protocol for multi‐server communication environment, introduced by Hsiang and Shih, is evaluated. Our security analysis indicates that their scheme is insecure against session key disclosure, server spoofing attack, and replay attack and behavior denial. Copyright © 2010 John Wiley & Sons, Ltd.     

Design of a user anonymous password authentication scheme without smart card

Recently, Jiang et al. and He et al. independently found security problems in Chen et al.'s remote user authentication scheme for non‐tamper‐proof storage devices like Universal Serial Bus stick and proposed improvements. Nonetheless, we detect that the schemes proposed by Jiang et al. and He et al. overlook a user's privacy. We also observe that Jiang et al.'s scheme is vulnerable to insider attack and denial of service attacks and lacks forward secrecy. We point out that the password changing facility in He et al.'s scheme is equivalent to undergoing registration, whereas in Jiang et al.'s scheme, it is unsuitable. Moreover, the login phase of both the schemes is incapable to prevent the use of wrong password leading to the computation of an unworkable login request. Therefore, we design a new scheme with user anonymity to surmount the identified weaknesses. Without adding much in communication/computational cost, our scheme provides more security characteristics and keeps the merits of the original schemes. As compared with its predecessor schemes, the proposed scheme stands out as a more apt user authentication method for common storage devices. We have also presented a formal proof of security of the proposed scheme based on the logic proposed by Burrows, Abadi and Needham (BAN logic). Copyright © 2014 John Wiley & Sons, Ltd.