Annotations languages:

** Description:** The article solves the practical task of constructing a digital system for information transmission and displaying in the form of multi-digit numbers with the protection of the numbers of each digit from unauthorized access and errors. Their numbers are in binary-decimal form and are encoded with 4 bits. The numbers after the transmission are displayed on the indicators. The simplicity of the proposed algorithms allows them to be implemented on one PLD chip. This ensures a sufficient level of reliability and performance of the device at its insignificant cost. The secrecy of the transmitted multi-bit numbers is achieved separately for each digit number using a special substitution cipher, which, in each of ten binary-decimal digits, correlates with another binary-decimal digit selected randomly. As a result, the cipher for a single digit of a multivalued number represents a randomly taken permutation of 10 binary-decimal digits. These ciphers can easily be changed if necessary, which ensures their high stability. In addition to the cipher in the form of substitutions in each level, in the multi-bit number, there are also permutations of discharges, which greatly raises the reliability of the cipher as a whole. Errors in the transmission of binary-decimal digits in encrypted form are detected using an equilibrium code and the presence of 6 forbidden combinations for each digit being transmitted. The same keys have the form of permutations of 10 digits, and therefore they have redundancy, which can be used to raise their noise immunity in storage and transmission. Therefore, in general, the system for transmitting and displaying information being developed is protected from both unauthorized access and errors.

**
Keywords:
** information transmission system, unauthorized access, permutations, encryption tables, noise immunity, equilibrium code

1. Vorobey, R.I., Gusev, O.K., Svistun, A.I., Tyavlovskiy, A.K., Tyavlovskiy, K.L. and Shadurskaya, L.I. (2018), ”Izmeritelnyye preobrazovateli sistem opticheskoy diagnostiki s mnogofunktsionalnymi odnoelementnymi fotopriyemnikami” [Measuring transducers of optical diagnostics systems with multi-functional single-element photodetectors], Pribory i metody izmereniy, 2018, Vol. 9, No. 3, pp. 215-226.

2. Borysenko, Olexiy A. and Kalashnikov, Vyacheslav V. (2017), Chapter 7: Description and applications of binomial numeral systems complex, Security and noise immunity of telecommunication systems: new solutions to the codes and signals design problem: Collective monograph, ASC Academic Publishing, Minden, Nevada, USA, pp. 147-159.

3. Kuznetsov, Alexandr A., Serhiienko, Roman V., Prokopovych-Tkachenko, Dmytro I. and Akhmetov, Bakhytzhan S. (2017), Chapter 3: Representation of cascade codes in the frequency domain, Security and noise immunity of telecommunication systems: new solutions to the codes and signals design problem: Collective monograph, ASC Academic Publishing, Minden, Nevada, USA, pp. 71-101.

4. Kuznetsov, Alexandr A., Ksvun, Sergii V. and Gorbenko, Yuriy I. (2017), Chapter 4: The methodology of evaluating the energy gains from coding in channels with grouping errors, Security and noise immunity of telecommunication systems: new solutions to the codes and signals design problem: Collective monograph, ASC Academic Publishing, Minden, Nevada, USA, pp. 102-119.

5. Goryachev, A.E. (2009), “Obnaruzheniye oshibok v perestanovkakh” [Detection of errors in permutations], Visnik SumDU. Tekhnichni nauki, No. 3, pp. 169-174.

6. Borisenko, A.A., Goryachev, A.E. and Onanchenko, E.L. (2010), “Obnaruzheniye i ispravleniye oshibok v perestanovkakh” [Detection and correction of errors in permutations], Mіzhnarodna naukovo-praktichna konferentsіya “Іnformatsіynі tekhnologії ta komp’yuterna іnzhenerіya”, VNTU, Vіnnitsya, pp. 348-349.

7. Borisenko, Alexei A., Kalashnikov, Vyacheslav V., Kalashnykova, Nataliya I. and Goryachev, Alexey E. (2014), Chapter 11: A Generalized Criterion of Efficiency for Telecommunication Systems, Computer Vision in Advanced Control Systems Using Conventional and Intelligent Paradigms (Springer Series: Intelligent Systems Reference Library, ISSN 1868-4394), Springer-Verlag, Alemania, Vol. 1, pp. 353-373, available at: http://www.springer.com/series/8578.

8. Shennon, K. (1963), “Raboty po teorii informatsii i kibernetike” [Works on information theory and cybernetics], Inostrannaya literatura, Moscow, 832 p.

9. Stollings, V. (2001), “Kriptografiya i zashchita setey: printsipy i praktika” [Works on information theory and cybernetics], Viliams, Moscow, 672 p.

10. Moldovyan, A.A., Moldovyan, N.A., Guts, N.D. and Izotov, B.V. (2002), “Kriptografiya: skorostnyye shifry” [Cryptography: speed ciphers], BHV-Peterburg, Sankt Peterburg, 244 p.

11. Borisenko, A.A., Kalashnikov, V.V., Kulik, I.A. and Goryachev, A.E. (2008), “Generation of Permutations Based Upon Factorial Numbers”, Eighth International Conference on Intelligent Systems Design and Applications, Kaohiung, Taiwan, pp. 57-61.

12. Borisenko, A., Goryachev, A., Serdyuk, V. and Ermakov, M. (2018), “Faktorialnyye chisla v zadachakh zashchity informatsii” [Factorial numbers in information security tasks], Ukrainian Scientific Journal of Information Security, Vol. 24, No. 3, pp. 169-174.

Borysenko, O.A., Berezhna, O.V., Novhorodtsev, A.I., Serdiuk, V.V. and Yakovlev, M.M. (2019), “Systema peredachi ta vidobrazhennia informatsii iz zakhystom chyslovykh danykh” [Information transmission and display system with protection of numerical data],