225 research outputs found

    Cryptanalysis of and Improvement on Biometric-based User Authentication Scheme for C/S System

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    Password-based authentication schemes are convenient, but vulnerable to simple dictionary attacks. Cryptographic secret keys are safe, but difficult to memorize. More recently, biometric information has been used for authentication schemes. Das proposed a biometric-based authentication scheme, but it has various vulnerabilities. Jiping et al. improved Das’s scheme, but some vulnerabilities remain. In this paper, we analyze the cryptanalysis of Jiping et al.’s authentication scheme and propose the security enhanced biometric-based user authentication scheme for the C/S System

    Cryptanalysis and Improvement on Robust Three-Factor Remote User Authentication Scheme with Key Agreement for Multimedia System

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    A three-factor authentication combines biometrics information with user password and smart card to provide security-enhanced user authentication. An proposed user authentication scheme improved Das’s scheme. But An’s scheme is not secure against denial of service attack in login phase, forgery attack. Li et al. pointed out them and proposed three-factor remote user authentication scheme with key agreement. However, Li et al’s scheme still has some security problem. In this paper, we present a cryptanalysis and improvement of Li et al.’s remote user authentication scheme

    DECENTRALIZED SOCIAL NETWORK SERVICE USING THE WEB HOSTING SERVER FOR PRIVACY PRESERVATION

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    In recent years, the number of subscribers of the social network services such as Facebook and Twitter has increased rapidly. In accordance with the increasing popularity of social network services, concerns about user privacy are also growing. Existing social network services have a centralized structure that a service provider collects all the user’s profile and logs until the end of the connection. The information collected typically useful for commercial purposes, but may lead to a serious user privacy violation. The user’s profile can be compromised for malicious purposes, and even may be a tool of surveillance extremely. In this paper, we remove a centralized structure to prevent the service provider from collecting all users’ information indiscriminately, and present a decentralized structure using the web hosting server. The service provider provides only the service applications to web hosting companies, and the user should select a web hosting company that he trusts. Thus, the user’s information is distributed, and the user’s privacy is guaranteed from the service provider

    A Weakness in Jung-Paeng-Kim\u27s ID-based Conference Key Distribution Scheme

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    Very recently, Jung, Paeng and Kim [IEEE Communications Letters, Vol 8, No 7, pp 446--448, July 2004] have demonstrated the insecurity of Xu and Tilborg\u27s ID-based conference key distribution scheme, and in addition, have revised the scheme to fix the security flaws discovered by them. However, in this paper, we show that Jung-Paeng-Kim\u27s revised scheme is still insecure since it is vulnerable to an active attack of colluding adversaries. We also show that our attack can be easily thwarted by a simple patch

    Constant Round Group Key Exchange with Logarithmic Computational Complexity

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    Protocols for group key exchange (GKE) are cryptographic algorithms that describe how a group of parties communicating over a public network can come up with a common secret key. Due to their critical role in building secure multicast channels, a number of GKE protocols have been proposed over the years in a variety of settings. However despite many impressive achievements, it still remains a challenging problem to design a secure GKE protocol which scales very well for large groups. Our observation is that all provably-secure constant-round GKE protocols providing forward secrecy thus far are not fully scalable, but have a computational complexity that scales only linearly in group size. Motivated by this observation, we propose a new GKE protocol that not only offers full scalability in all directions but also attains provable security against active adversaries. Full scalability is achieved by using a complete binary tree structure where users are arranged on both internal and leaf nodes. Security is proved via reduction to the decisional Diffie-Hellman assumption in a well-defined formal model of communication and adversarial capabilities

    Security Weakness in a Three-Party Password-Based Key Exchange Protocol Using Weil Pairing

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    Recently, Wen, Lee, and Hwang proposed a three-party password-authenticated key exchange protocol making use of the Weil pairing. The protocol was claimed to be provably secure. But despite the claim of provable security, the protocol is in fact insecure in the presence of an active adversary. We demonstrate this by presenting an attack that completely compromises the authentication mechanism of the protocol. Consequently, the proof of security for the protocol is invalidated

    A weakness in Sun-Chen-Hwang\u27s three-party key agreement protocols using passwords

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    Recently, Sun, Chen and Hwang [J. Syst. Software, 75 (2005), 63-68] have proposed two new three-party protocols, one for password-based authenticated key agreement and one for verifier-based authenticated key agreement. In this paper, we show that both of Sun-Chen-Hwang\u27s protocols are insecure against an active adversary who can intercept messages, start multiple sessions of a protocol, or otherwise control the communication in the network. Also, we present a simple solution to the security problem with the protocols

    Attacks on Bresson-Chevassut-Essiari-Pointcheval\u27s Group Key Agreement Scheme for Low-Power Mobile Devices

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    In this paper, we show that Bresson-Chevassut-Essiari-Pointcheval\u27s group key agreement scheme does not meet the main security properties: implicit key authentication, forward secrecy, and known key security. Also, we propose an improved version which fixes the security flaws found in the scheme

    A mechanical approach to derive identity-based protocols from Diffie-Hellman-based protocols

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    We describe a mechanical approach to derive identity-based (ID-based) protocols from existing Diffie-Hellman-based ones. As case studies, we present the ID-based versions of the Unified Model protocol, UMP-ID, Blake-Wilson, Johnson & Menezes (1997)\u27s protocol, BJM-ID, and Krawczyk (2005)\u27s HMQV protocol, HMQV-ID. We describe the calculations required to be modified in existing proofs. We conclude with a comparative security and efficiency of the three proposed ID-based protocols (relative to other similar published protocols) and demonstrate that our proposed ID-based protocols are computationally efficient
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