International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 15 September 2015

Richard Winter, Ana Salagean, Raphael C.-W. Phan
ePrint Report ePrint Report
We generalise the cube attack of Dinur and Shamir (and the similar AIDA attack of Vielhaber) to a more general higher order differentiation attack, by summing over an arbitrary subspace of the space of initialisation vectors. The Moebius transform can be used for efficiently examining all the subspaces of a big space, similar to the method used by Fouque and Vannet for the usual cube attack. Secondly we propose replacing the Generalised Linearity Test proposed by Dinur and Shamir with a test based on higher order differentiation/ Moebius transform. We show that the proposed test provides all the information provided by the Generalised Linearity Test, at the same computational cost. In addition, for functions that do not pass the linearity test it also provides, at no extra cost, an estimate of the degree of the function. This is useful for guiding the heuristics for the cube/AIDA attacks. Finally we implement our ideas and test them on the stream cipher Trivium.

Expand

Additional news items may be found on the IACR news page.