[Resource Topic] 2010/282: Pseudo-Linear Approximations for ARX Ciphers: With Application to Threefish

Welcome to the resource topic for 2010/282

Title:
Pseudo-Linear Approximations for ARX Ciphers: With Application to Threefish

Authors: Kerry A. McKay, Poorvi L. Vora

Abstract:

The operations addition modulo 2^n and exclusive-or have recently been combined to obtain an efficient mechanism for nonlinearity in block cipher design. In this paper, we show that ciphers using this approach may be approximated by pseudo-linear expressions relating groups of contiguous bits of the round key, round input, and round output. The bias of an approximation can be large enough for known plaintext attacks. We demonstrate an application of this concept to a reduced-round version of the Threefish block cipher, a component of the Skein entry in the secure hash function competition.

ePrint: https://eprint.iacr.org/2010/282

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .