MarriageTheoremのこと

_ arXiv:math 2012年11月28日分まで、IACR ePrint 2013/023まで確認済み

_ 気になった論文：Nonlinear cryptanalysis of reduced-round Serpent and metaheuristic search for S-box approximations, James McLaughlin and John A. Clark, http://eprint.iacr.org/2013/022

We utilise a simulated annealing algorithm to find several nonlinear approximations to various S-boxes which can be used to replace the linear approximations in the outer rounds of existing attacks. We propose three variants of a new nonlinear cryptanalytic algorithm which overcomes the main issues that prevented the use of nonlinear approximations in previous research, and we present the statistical frameworks for calculating the complexity of each version. We present new attacks on 11-round Serpent with better data complexity than any other known-plaintext or chosen-plaintext attack, and with the best overall time complexity for a 256-bit key.