The paper studies the procedure for restoring discreet segments of an unknown source message based on information about possible variants of each sign. An algorithm is proposed based on compiling dictionaries of appropriate lengths, searching for text sections with a total number of character variants that do not exceed a given boundary, and then iterating through and eliminating false variants of dictionary values. Statistical properties of short-length text dictionaries are investigated, and extrapolation estimates are made for long-length texts. The main mathematical properties of this algorithm are described. Theoretical studies of the effectiveness of the procedure under consideration are carried out within the framework of a certain probability-theoretical model.