Cryptology ePrint Archive: Report 2004/136

CompChall: Addressing Password Guessing Attacks

Vipul Goyal and Virendra Kumar and Mayank Singh and Ajith Abraham and Sugata Sanyal

Abstract: Even though passwords are the most convenient means of authentication, they bring along themselves the threat of dictionary attacks. Dictionary attacks may be of two kinds: online and offline. While offline dictionary attacks are possible only if the adversary is able to collect data for a successful protocol execution by eavesdropping on the communication channel and can be successfully countered using public key cryptography, online dictionary attacks can be performed by anyone and there is no satisfactory solution to counter them. This paper presents a new authentication protocol which is called CompChall (computational challenge). The proposed protocol uses only one way hash functions as the building blocks and attempts to eliminate online dictionary attacks by implementing a challenge-response system. This challenge-response system is designed in a fashion that it does not pose any difficulty to a genuine user but is time consuming and computationally intensive for an adversary trying to launch a large number of login requests per unit time as in the case of an online dictionary attack. The protocol is stateless and thus less vulnerable to DoS (Denial of Service) attacks.

Category / Keywords: cryptographic protocols /

Publication Info: Information Assurance and Security Track, ITCC-2005, USA, IEEE Computer Society, April 2005

Date: received 5 Jun 2004, last revised 30 Dec 2006

Contact author: vipul goyal at cse04 itbhu org

Available format(s): PDF | BibTeX Citation

Version: 20061230:180658 (All versions of this report)

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