SUMMARY
The algorithm of data encryption using discrete chaotic systems and transformations is considered. The features of reversible discrete control systems as information transformers are studied, in particular, such a property as dynamic degradation. It consists in the possible sharp decrease of a discrete set of states of a complex dynamic system with the introduction of an information message. To a large extent, this phenomenon depends on the initial values of the trajectories and parameters of the system. An example of a dynamic system whose trajectories have a complex internal dynamic is given, but when an information message is introduced into it, they fall on a zero invariant manifold. Thus, instead of encrypting the input information sequence, the output of the system for any values of key parameters, starting from a certain moment, accurately transmits the value of the information input with a unit delay.