The theory of linear finite-state machines (LFSM) for presentation of a scrambler and stream cipher which using the shifting register is suggested. The model of operation of additive and self-synchronized scramblers based on the mathematical representation of time symmetry is considered. The method of reconstruction of the unknown pseudo-random sequence in the reverse order with the linear complexity by using its known r-bit fragment with the help of r-bit LFSM is offered.
scrambler, cryptography, stream encryption, linear finite-state machine, time, reversible automaton
"Rekonstruktsyia lyneinыkh skremblerov na osnove avtomatnыkh modelei" [Reconstruction of linear scramblers based on automaton models],
Information Processing Systems,