On key schedule for block ciphers without week keys

This paper describes the key schedule providing all different round keys for $r$-round symmetric block cipher. The key schedule is implemented by a series connection of automata: an autonomous automaton $A$ generating an output sequence of binary vectors with the period length is not less than $r$, and internally autonomous automaton with permanent memory containing the encryption key of a block cipher. As an example, a linear shift register with a maximum period is considered as the automaton $A$.