from Hacker News

Possible cooked S-boxes in Kuznyechik & Streebog..Russian cipher & hash

by utefan001 on 2/11/19, 3:27 AM with 3 comments

• by ggm on 2/11/19, 10:43 AM

  The sentence which seems critical in his posting is maybe this one: Arnaud Bannier proved in his PhD (see also [3]) that an S-box preserving a partition of the space into additive cosets in such a way that it interacts with the linear layer was necessary to build some specific backdoors.

  I am not a cryptographer or a mathematician. These words do seem very worrying to me. He seems to be saying the primary quality, the preservation of a property across sbox and linear layer was demonstrated.

• by dsl on 2/11/19, 8:09 AM

  These are both GOST R (ГОСТ) standards, which is the Russian equivalent of NIST standards.

• by jdashg on 2/11/19, 5:29 AM

  I know some of these words. This sounds Bad.