By: Francisco Blas Izquierdo Riera (Klondike)

Scheduled on: January 27 at 14:00

Contributor analysis is a simple cryptanalysis technique which allows detecting and attacking blatantly broken cryptographic algorithms and implementations. Although the technique is inspired by the techniques employed by algebraic approaches it aims at being much simpler to understand and reason with, making it possible not only to automate the testing but also to even run tests using pen and paper.

In this talk we will introduce the participants to this technique, explain briefly the theoretic principles that make it work and how it relates to algebraic cryptanalysis and then explain how to handle contributor lists with different common operations. We will explain how these lists can be used to mount an attack therefore proving why a succesfully attacked cipher can be considered broken. Finally we will show some simple examples of ciphers affected by these techniques.

No mathematical nor cryptographical knowledge is needed to follow this talk although some programming or computer architecture knowledge is recommended.