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Project Overview

Started by Cruncher Pete, May 21, 2009, 11:59:52 AM

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Cruncher Pete


Project Summary
The hash function SHA-1 (see e.g. wikipedia) is one of the most important cryptographic building blocks used today. It was designed by NSA and put forward as a standard by NIST in 1995. Browsing the Web, administering severs via ssh, or storing and comparing passwords are just a few examples where SHA-1 is used and trusted by many of us on a daily basis.
Most predecessors of SHA-1 were broken, i.e. collisions have been found:
The German cryptographer Hans Dobbertin found a pair of colliding messages for MD4 in 1996.
In 2004, a group of Chinese researchers around Prof. Wang found the first collisions for MD5 and RIPEMD.
Independently and shortly afterwards a French group around Antoine Joux reported a collision for SHA-0 (or alternatively called SHA), the direct predecessor of SHA-1.
So far nobody could show a collision for SHA-1, since SHA-1 is much more resistant against these style of attacks.
However, researchers define variants where they reduce the number of steps. The variant which comes closest to the real SHA-1 for which a colliding message pair was found is SHA-1 reduced to 70 out of 80 steps. Note however that the workload grows exponentially with the number of steps. This implies that a hash function for which there is an attack on a variant with only half the number of steps is by no means 'half broken'.
As soon as the input to a hash function can get longer than the output, collisions between inputs are unavoidable. For a hash function with n bit output size, a birthday attack (see e.g. wikipedia) requires about 2n/2 hash operations to find a colliding message pair. A dedicated attack, on the other hand, tries to exploit the inner working of the hash function. The SHA-1-Collison Search Graz Project is of that type.

The following platforms are supported:

Microsoft Windows x86    (32bit)
Linux x86                       (32bit)
Linux x86_64                  (64bit)

Connecting to SHA1 Collision
The project's Home Page is located at:
SHA1 Collision Search is also listed in the various BOINC Account Managers and you can join the project through them directly.
Don't forget to join BOINC@Australia Team following your registration.

View our Team Members List and their current score here
View detailed BOINCStats for our SHA1 Collision Team here