A method for building a cryptographic generator of sequences with specified index of unrepeatability
It is known that iterative symmetric block ciphers may have a few specific keys termed "weak keys" and "semi-weak keys". Due to this fact, we consider a method for constructing the key schedule providing the absence of duplication in round key sequence. For key generation, we propose the autonomous automaton based on one-two step generator consisting of two maximal period linear feedback shift registers of length n and m. The output alphabet of this automaton is Vm and the subsequence of length 2does not contain repeating vectors for any initial state of the automaton.
Keywords
block cipher, round key, r-unrepeatable sequence, r-unrepeatable automaton, index of unrepeatability, блочный шифр, раундовый ключ, r-бесповторная последовательность, r-бесповторный автомат, показатель бесповторностиAuthors
Name | Organization | |
Romanko D.A. | National Research Nuclear University (MEPI) | dmax.rda@gmail.com |
Fomichev V. M. | National Research Nuclear University (MEPI) | fomichev@nm.ru |
References

A method for building a cryptographic generator of sequences with specified index of unrepeatability | Applied Discrete Mathematics. Supplement. 2016. № 9.