In given clause the author considers an operating mode of hierarchical system joint crypto-and imito-protection of the information with use alternates codes at a stage of generation q-ary key sequences. For the given system in clause the top and bottom borders of linear complexity of the sequences received as a result of a nonlinear combination q-ary sequences, read out with various outputs of the same linear registers of shifts with feedback are resulted. It is shown, that the number of sequences with the maximal linear complexity in a limit is infinitely great and in a limit compared with the general number of sequences with the set characteristic polynomial. The conditions shown to nonlinear function of a combination at which linear complexity of sequence satisfies to the top border are formulated.