EN|RU Volume 20, No 5, 2013, P. 58-65 UDC 519.7 Pestunov A. I. An impact of the two values difference’s Hamming weight on its preserving probability after addition and subtraction Abstract: We study how difference propagation probability depends on its Hamming weight. The difference of two values is XOR, an operation usual for differential cryptanalysis. We prove that the difference preserves with probability $2^{-h}$ if the most significant bit is 0, and with probability $2^{-(h-1)}$ if this bit is 1, where $h$ is the difference's Hamming weight. Theoretical results are confirmed experimentally. Bibliogr. 13. Keywords: differential cryptanalysis, block cipher, characteristic. Pestunov Andrey Igorevich 1,2 1. Novosibirsk State University of Economics and Management, 56 Kamenskaya Ave., 630099 Novosibirsk, Russia 2. Institute of Computational Technologies SB RAS, 6 Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia e-mail: pestunov@gmail.com © Sobolev Institute of Mathematics, 2015