An Improved and Secure Two-factor Dynamic ID Based Authenticated Key Agreement Scheme for Multiserver Environment

The smart card based password authentication scheme is one of the most important and efficient security mechanism, which is used for providing security to authorized users over an insecure network. In this paper, we analyzed major security flaws of Jangirala et al.’s scheme and proved that it is vulnerable to forgery attack, replay attack, user impersonation attack. Also, Jangirala et al.’s scheme fail to achieve mutual authentication as it claimed. We proposed an improved two factor based dynamic ID based authenticated key agreement protocol for the multiserver environment. The proposed scheme has been simulated using widely accepted AVISPA tool. Furthermore, mutual authentication is proved through BAN logic. The rigorous security and performance analysis depicts that the proposed scheme provides users anonymity, mutual authentication, session key agreement and secure against various active attacks.     

An improved lightweight multiserver authentication scheme

Multiserver authentication complies with the up‐to‐date requirements of Internet services and latest applications. The multiserver architecture enables the expedient authentication of subscribers on an insecure channel for the delivery of services. The users rely on a single registration of a trusted third party for the procurement of services from various servers. Recently, Chen and Lee, Moon et al, and Wang et al presented multiserver key agreement schemes that are found to be vulnerable to many attacks according to our analysis. The Chen and Lee scheme was found susceptible to impersonation attack, trace attack, stolen smart card attack exposing session key, key‐compromise impersonation attack, and inefficient password modification. The Moon et al is susceptible to stolen card attack leading to further attacks, ie, identity guessing, key‐compromise impersonation attack, user impersonation attack, and session keys disclosure, while Wang et al is also found to be prone to trace attack, session‐specific temporary information attack, key‐compromise information attack, and privileged insider attack leading to session key disclosure and user impersonation attacks. We propose an improved protocol countering the indicated weaknesses of these schemes in an equivalent cost. Our scheme demonstrates automated and security analysis on the basis of Burrows‐Abadi‐Needham logic and also presents the performance evaluation for related schemes.     

Secure user authentication scheme with novel server mutual verification for multiserver environments

The fast growth of mobile services and devices has made the conventional single‐server architecture ineffective from the point of its functional requirements. To extend the scalability and availability of mobile services to various applications, it is required to deploy multiserver architecture. In 2016, Moon et al insisted that Lu et al's scheme is weak to insiders and impersonation attack, then they proposed a biometric‐based scheme for authentication and key agreement of users in multiserver environments. Unfortunately, we analyze Moon et al's scheme and demonstrate that their scheme does not withstand various attacks from a malicious registered server. We propose a user authentication scheme with server mutual verification to overcome these security drawbacks. The proposed scheme withstands an attack from malicious insiders in multiserver environments. We use a threshold cryptography to strengthen the process of server authorization and to provide better security functionalities. We then prove the authentication and session key of the proposed scheme using Burrows‐Abadi‐Needham (BAN) logic and show that our proposed scheme is secure against various attacks.     

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.     

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.     

An enhanced bilinear pairing based authenticated key agreement protocol for multiserver environment

To circumvent using of multiple single servers, the theory of multiserver communication exists and numerous authentication protocols put forward for providing secure communication. Very recently, Amin‐Biswas proposes bilinear pairing–based multiserver scheme by describing some security pitfalls of Hsieh‐Leu protocol and claims that it is secured against related security threats. However, this paper claims that Amin‐Biswas protocol is still susceptible to off‐line identity and password guessing attack, user untraceability attack, and server masquerading attack. The cryptographic protocol should be attacks‐free for real‐time application. To achieve attacks‐free security, we put forward smart card–based multiserver authentication protocol by using the concept of bilinear pairing operation. The formal method strand space model has been used to prove the correctness of the proposed scheme. Additionally, rigorous security analysis ensures pliability of common security threats. The performance and security features of our scheme are also compared with that of the similar existing schemes. The comparison results show that our protocol achieves more security features with less complexity.     

An anonymous and untraceable password‐based authentication scheme for session initiation protocol using smart cards

Recently, Zhang et al. proposed a password‐based authenticated key agreement for session initiation protocol (Int J Commun Syst 2013, doi:10.1002/dac.2499). They claimed that their protocol is secure against known security attacks. However, in this paper, we indicate that the protocol by Zhang et al. is vulnerable to impersonation attack whereby an active adversary without knowing the user's password is able to introduce himself/herself as the user. In addition, we show that the protocol by Zhang et al. suffers from password changing attack. To overcome the weaknesses, we propose an improved authentication scheme for session initiation protocol. The rigorous analysis shows that our scheme achieves more security than the scheme by Zhang et al. Copyright © 2014 John Wiley & Sons, Ltd.     

An improved and secure multiserver authentication scheme based on biometrics and smartcard

With the advancement in internet technologies, the number of servers has increased remarkably to provide more services to the end users. These services are provided over the public channels, which are insecure and susceptible to interception, modification, and deletion. To provide security, registered entities are authenticated and then a session key is established between them to communicate securely. The conventional schemes allow a user to access services only after their independent registration with each desired server in a multiserver system. Therefore, a user must possess multiple smartcards and memorize various identities and passwords for obtaining services from multiple servers. This has led to the adoption of multiserver authentication in which a user accesses services of multiple servers after registering himself at only one central authority. Recently, Kumar and Om discussed a scheme for multiserver environment by using smartcard. Since the user-memorized passwords are of low entropy, it is possible for an attacker to guess them. This paper uses biometric information of user to enhance the security of the scheme by Kumar and Om. Moreover, we conducted rigorous security analyses (informal and formal) in this study to prove the security of the proposed scheme against all known attacks. We also simulated our scheme by using the automated tool, ProVerif, to prove its secrecy and authentication properties. A comparative study of the proposed scheme with the existing related schemes shows its effectiveness.     

An efficient and secure 3‐factor user‐authentication protocol for multiserver environment

In the last decade, the number of web‐based applications is increasing rapidly, which leads to high demand for user authentication protocol for multiserver environment. Many user‐authentication protocols have been proposed for different applications. Unfortunately, most of them either have some security weaknesses or suffer from unsatisfactory performance. Recently, Ali and Pal proposed a three‐factor user‐authentication protocol for multiserver environment. They claimed that their protocol can provide mutual authentication and is secure against many kinds of attacks. However, we find that Ali and Pal's protocol cannot provide user anonymity and is vulnerable to 4 kinds of attacks. To enhance security, we propose a new user‐authentication protocol for multiserver environment. Then, we provide a formal security analysis and a security discussion, which indicate our protocol is provably secure and can withstand various attacks. Besides, we present a performance analysis to show that our protocol is efficient and practical for real industrial environment.     

Cryptanalysis of smart‐card‐based password authenticated key agreement protocol for session initiation protocol of Zhang et al.

As the core signaling protocol for multimedia services, such as voice over internet protocol, the session initiation protocol (SIP) is receiving much attention and its security is becoming increasingly important. It is critical to develop a roust user authentication protocol for SIP. The original authentication protocol is not strong enough to provide acceptable security level, and a number of authentication protocols have been proposed to strengthen the security. Recently, Zhang et al. proposed an efficient and flexible smart‐card‐based password authenticated key agreement protocol for SIP. They claimed that the protocol enjoys many unique properties and can withstand various attacks. However, we demonstrate that the scheme by Zhang et al. is insecure against the malicious insider impersonation attack. Specifically, a malicious user can impersonate other users registered with the same server. We also proposed an effective fix to remedy the flaw, which remedies the security flaw without sacrificing the efficiency. The lesson learned is that the authenticators must be closely coupled with the identity, and we should prevent the identity from being separated from the authenticators in the future design of two‐factor authentication protocols. Copyright © 2014 John Wiley & Sons, Ltd.     

A Secure and Effective Anonymous Authentication Scheme for Roaming Service in Global Mobility Networks

Recently, Mun et al. analyzed Wu et al.’s authentication scheme and proposed an enhanced anonymous authentication scheme for roaming service in global mobility networks. However, through careful analysis, we find that Mun et al.’s scheme is vulnerable to impersonation attacks and insider attacks, and cannot provide user friendliness, user’s anonymity, proper mutual authentication and local verification. To remedy these weaknesses, we propose a novel anonymous authentication scheme for roaming service in global mobility networks. Compared with previous related works, our scheme has many advantages. Firstly, the secure authenticity of the scheme is formally validated by an useful formal model called BAN logic. Secondly, the scheme enjoys many important security attributes including prevention of various attacks, user anonymity, no verification table, local password verification and so on. Thirdly, the scheme does not use timestamp, thus it avoids the clock synchronization problem. Further, the scheme contains the authentication and establishment of session key scheme when mobile user is located in his/her home network, therefore it is more practical and universal for global mobility networks. Finally, performance and cost analysis show our scheme is more suitable for low-power and resource limited mobile devices and thus availability for real implementation.     

An Improved User Authentication and Key Agreement Scheme Providing User Anonymity

When accessing remote services over public networks, a user authentication mechanism is required because these activities are executed in an insecure communication environment. Recently, Wang et al. proposed an authentication and key agreement scheme preserving the privacy of secret keys and providing user anonymity. Later, Chang et al. indicated that their scheme suffers from two security flaws. First, it cannot resist DoS (denial-of-service) attack because the indicators for the next session are not consistent. Second, the user password may be modified by a malicious attacker because no authentication mechanism is applied before the user password is updated. To eliminate the security flaws and preserve the advantages of Wang et al.'s scheme, we propose an improvement in this paper.     

A secure and efficient identity‐based mutual authentication scheme with smart card using elliptic curve cryptography

The e‐commerce has got great development in the past decades and brings great convenience to people. Users can obtain all kinds of services through e‐commerce platform with mobile device from anywhere and at anytime. To make it work well, e‐commerce platform must be secure and provide privacy preserving. To achieve this goal, Islam et al. proposed a dynamic identity‐based remote user mutual authentication scheme with smart card using Elliptic Curve Cryptography(ECC). Islam et al claimed that the security of their scheme was good enough to resist various attacks. However, we demonstrate that their scheme is vulnerable to insider attack and suffers from off‐line password guessing attack if smart card is compromised. To overcome the deficiencies, we present an improved scheme over Islam's scheme. The security proof and analysis shows that our scheme can also provide user anonymity and mutual authentication, and the security is enough to against relay attack, impersonation attack, and other common secure attackers. The performance analysis shows that the proposed scheme is more efficient than Islam et al's scheme.     

A lightweight password‐based authentication protocol using smart card

With its simplicity and feasibility, password‐based remote user authentication becomes a popular way to control remote access to network. These years, numerous password‐based authentication schemes have been proposed. Recently, Maitra et al proposed a smart card–based scheme which claims to be resistant to various attacks. Unfortunately, we found some important flaws in this scheme. Therefore, in this paper, we will demonstrate that the scheme of Maitra et al is not secure enough as claimed: neither resisting against off‐line password guessing attack and insider attack nor preserve forward secrecy. To overcome those flaws, we put forward an improved new scheme which not only is resistant to all known attacks but also provides many attractive attributes, such as user revocation and re‐register. Also, we compared the scheme with other related schemes, the result proved the superiority of our scheme. Particularly, we show a new way (beyond the conventional Deffie‐Hellman approach) to achieve forward secrecy. Furthermore, we put some efforts into exploring the design principle of authentication schemes.     

ID-Based User Authentication Scheme for Cloud Computing

In cloud computing environments, user authentication is an important security mechanism because it provides the fundamentals of authentication, authorization, and accounting (AAA). In 2009, Wang et al. proposed an identity-based (ID-based) authentication scheme to deal with the user login problem for cloud computing. However, Wang et al.'s scheme is insecure against message alteration and impersonation attacks. Besides, their scheme has large computation costs for cloud users. Therefore, we propose a novel ID-based user authentication scheme to solve the above mentioned problems. The proposed scheme provides anonymity and security for the user who accesses different cloud servers. Compared with the related schemes, the proposed scheme has less computation cost so it is very efficient for cloud computing in practice.     

An anonymous biometric‐based remote user‐authenticated key agreement scheme for multimedia systems

We analyze the security of the Li et al . authentication scheme and show its vulnerability to off‐line password‐guessing and replay attacks. We design a new anonymous authentication scheme. The proposed scheme not only removes the drawback of the scheme of the Li et al . scheme but also protects user's anonymity. Moreover, we show validity of our proposed scheme using Burrows, Abadi, and Needham logic. Our scheme is comparable in terms of the communication and computational overhead with related schemes. Copyright © 2015 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.     

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.     

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.     

Revised anonymous authentication protocol for adaptive client‐server infrastructure

Rapid evolution in information and communication technologies has facilitated us to experience mobile communication in our daily routine. Mobile user can only avail the services from the server, once he/she is able to accomplish authentication process successfully. In the recent past, several researchers have contributed diverse authentication protocols for mobile client‐server environment. Currently, Lu et al designed two‐factor protocol for authenticating mobile client and server to exchange key between them. Lu et al emphasized that their scheme not only offers invincibility against potential security threats but also offers anonymity. Although this article reveals the facts that their protocol is vulnerable against client and server impersonation, man‐in‐the‐middle, server key breach, anonymity violation, client traceability, and session‐specific temporary attacks, therefore, we have enhanced their protocol to mitigate the above mention vulnerabilities. The enhanced protocol's security strength is evaluated through formal and informal security analysis. The security analysis and performance comparison endorses the fact that our protocol is able to offer more security with least possible computation complexity.