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Ophcrack is a Windows password cracker based on a time-memory trade-off using rainbow tables. This is a new variant of Hellman's original trade-off, with better performance.
This paper describes the use of Rainbow tables and compares their performance with the best variants that have been used before.
A simple explanation of rainbow tables. If you got a headache reading the first paper, this one is for you!
This french paper describes how to paramentrize rainbow tables to get the best performance and how to estimate the performance of the tables beforehand.
This paper describes a new improvement which significantly reduces cryptanalysis time while using only a minute amount of memory.
Time memory trade-offs also have laudable uses! In this paper we explain how rainbow tables can effectively protect your privacy.
The original Ophcrack v1.0a is available as Zipfile with sources, linux and windows binaries.
Free table sets for the Windows LM hash and for the Windows NT Hash are available on Sourceforge.
Links to commercial tables with larger character sets can also be found at the same place.
The on-line demo has moved to the web site of Objectif Securite. Feel free to go there and crack your alphanumerical passwords in seconds.
|alphanumeric passwords:||1.67 seconds|
|paswords with one non-alphanumeric half (half cracked):||26.14 seconds|
|passwords with two non-alphanumeric halves (not cracked):||42.14 seconds|