## Cryptology ePrint Archive: Report 2020/645

Correlation distribution analysis of a two-round key-alternating block cipher

Liliya Kraleva and Nikolai L. Manev and Vincent Rijmen

Abstract: In this paper we study two-round key-alternating block ciphers with round function $f(x)=x^{(2^t+1)2^s},$ where $t,s$ are positive integers. An algorithm to compute the distribution weight with respect to input and output masks is described. In the case $t=1$ the correlation distributions in dependence on input and output masks are completely determined for arbitrary pairs of masks. We investigate with more details the case $f(x)=x^3$ and fully derive and classify the distributions, proving that there are only 5 possible values for the correlation for any pair of masks.

Category / Keywords: foundations / correlation distribution, linear cryptanalysis, key-alternating ciphers, cube functions

Original Publication (in the same form): Tatra Mountains Mathematical Publications 73(1), 2019
DOI:
10.2478/tmmp-2019-0009

Contact author: liliya_kraleva at abv bg

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2020/645

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