Computer Journal

SHA1 Modulus Attack

by Javantea aka. Joel R. Voss
August 16, 2007

Source Code not yet available.

Introduction

Collisions in hashes are quite bad news for cryptographers. Finding them is quite difficult. The current best attack against SHA1 requires 2**69 operations.

Method

a is an array of plaintexts.
The likeliness of a collision is a function of len(a).
sha1mod1.py sha1 hashes the plaintexts modulus x.
It counts the collisions.
Plotted here is x vs collisions(x).

Data

SHA1 modulus x:

/dev/urandom modulus x:

Analysis

Analysis of this graph/data is not complete.

Conclusion

This article is not finished, but will be published with the next article of AltSci Concepts. Feel free to e-mail me.