Analyzing Pre-authentication Timestamps To Crack Kerberos V Passwords

Ahmed Alazzawe, Anis Alazzawe, Asad Nawaz, Duminda Wijesekera

2006

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.

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