2024, ЗАХАРОВ, Д. А., ПУДОВКИНА, М. А., Захаров, Дмитрий Александрович

Работа посвящена обзору атак на классы алгоритмов блочного шифрования Фейстеля методом невозможных разностей и исследованию слабостей алгоритмов, которые привели к возникновению атаки. В результате для алгоритмов приведены актуальные данные по числу раундов атаки и используемых слабостей.

2023, Zakharov, D., Pudovkina, M., Пудовкина, Марина Александровна, Захаров, Дмитрий Александрович

In this paper a family of l round balanced Feistel ciphers with non-bijective functions F is being considered. For any such algorithm, the existence of impossible differentials for an arbitrary number of rounds l is proved. Construction method and lower bound of the number of such impossible differentials is obtained. The GRANULE cipher belongs to the family under consideration, for which a new approach for finding impossible differentials is proposed. Its superiority in comparison with other previously known approaches is shown both in terms of the number of impossible differentials found and in terms of the number of rounds. Experimental confirmation of the theoretical bound of the number of impossible differentials has been obtained.