**4. Conclusions**

New AFG (Figure 1), built using prime numbers as modules of recurrent equations at specific values of modules, provide a constant repetition period of the output pseudorandom pulse sequence in the whole range of possible values of the initial settings keys (seed).

According to this property, the proposed Fibonacci generator differs favourably from the known Fibonacci generators, in which the value of the modulus is equal to the power of two. In contrast to the proposed device, in the known device, at *m* > 2, there are different values of the repetition periods, including those with critically small values. This indicates the presence of "weak keys". In addition, the maximum values of the repetition periods in the known device are usually smaller than the relative values of the module *m* of the proposed device.

When two pseudorandom pulse sequences combine through a logical element XOR, the period of the combined sequence is not less than the repetition period of each of them.

Combined PRBSG (Figure 4), under specific requirements for their construction, can provide the specified statistical characteristics and the absence of "weak keys" in the whole range of possible values of the initial settings–keys (seed).

The results obtained and presented in the article show that the proposed generators can be effectively used in cyber security, particularly as components of cryptographic information protection or noise generators for information security, or as noise-like code sequences of modern communication systems.

Perspective for further research is the development and analysis of other types of combined PRBSG with the possibility of their hardware implementation, as well as expanding the scope of such generators.

**Author Contributions:** Conceptualization, V.M., O.H., M.S.; Methodology, D.J., K.K., M.K.; Validation, D.J., K.K., V.M.; Formal Analysis, M.K., O.H., M.S.; Investigation, V.M., O.H., M.S., D.J., K.K., M.K.; Data Curation, V.M., O.H., M.S., M.K.; Writing—Original Draft Preparation, D.J., K.K., O.H., M.S.; Writing—Review and Editing, V.M., O.H., M.S, D.J., K.K., M.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
