Analyzing Pre-authentication Timestamps To Crack Kerberos V Passwords

Ahmed Alazzawe, Anis Alazzawe, Asad Nawaz, Duminda Wijesekera

Abstract

Platforms, including Microsoft Windows 2000/2003 Servers, utilize Kerberos V for authentication services. Kerberos V introduced several improvements over its predecessor including a pre-authentication scheme that authenticates KDC bound requests prior to issuing tickets. Timestamps are incorporated within the pre-authentication scheme causing a weakness. The time needed to obtain a password is decreased by capturing and subsequently utilizing this timestamp. This paper examines the computational efficiency obtained by utilizing the timestamp in attacking Kerberos V pre-authentication data. We developed a program that would parse the pre-authentication data in an attempt to recover the client’s password. It uses a well-known cryptographic library and one embodiment thereof omits the last HMAC computation used in the verification process. Instead a timestamp is used to determine the success of the decryption process. Our findings indicate that utilizing the timestamp saves considerable processing time.

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Paper Citation


in Harvard Style

Alazzawe A., Alazzawe A., Nawaz A. and Wijesekera D. (2006). Analyzing Pre-authentication Timestamps To Crack Kerberos V Passwords . In Proceedings of the 4th International Workshop on Security in Information Systems - Volume 1: WOSIS, (ICEIS 2006) ISBN 978-972-8865-52-8, pages 267-277. DOI: 10.5220/0002502802670277


in Bibtex Style

@conference{wosis06,
author={Ahmed Alazzawe and Anis Alazzawe and Asad Nawaz and Duminda Wijesekera},
title={Analyzing Pre-authentication Timestamps To Crack Kerberos V Passwords},
booktitle={Proceedings of the 4th International Workshop on Security in Information Systems - Volume 1: WOSIS, (ICEIS 2006)},
year={2006},
pages={267-277},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0002502802670277},
isbn={978-972-8865-52-8},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 4th International Workshop on Security in Information Systems - Volume 1: WOSIS, (ICEIS 2006)
TI - Analyzing Pre-authentication Timestamps To Crack Kerberos V Passwords
SN - 978-972-8865-52-8
AU - Alazzawe A.
AU - Alazzawe A.
AU - Nawaz A.
AU - Wijesekera D.
PY - 2006
SP - 267
EP - 277
DO - 10.5220/0002502802670277