DEVELOPMENT OF AN AUTHENTICATION METHOD BASED ON A MODIFIED MCELIECE SCHEME FOR DIGITAL RADIO STATIONS WITH POST-QUANTUM STABILITY

DOI: 10.31673/2409-7292.2025.041209

Abstract

In modern trunked radio systems such as Project 25 (P25), TETRA or DMR, ensuring strong authentication is key to
protecting against unauthorized access, subscriber device impersonation and radio resource theft. Trunked systems, where
channels are dynamically allocated for efficient group communication, are particularly vulnerable to cyber threats, including
MITM attacks, replay attacks and Subscriber Unit ID cloning. At the same time, there is a growing need to ensure security when
remotely managing the network infrastructure and supporting OTAR (Over-The-Air Rekeying) functions, which increases the
risk of key compromise when using traditional authentication methods. Traditional authentication methods based on symmetric
keys (e.g. AES in P25 Link Layer Authentication) provide a basic level of security, but are not resistant to future threats such
as quantum computing, which can break classical cryptography. In addition, existing solutions are often limited by the hardware
resources of subscriber devices. This reduces the effectiveness of comprehensive protection and the flexibility of network
scaling. The aim of the research is to develop an authentication method that integrates code-theoretic schemes to increase
cryptoresistance in trunked networks. The proposed method is based on a modification of the challenge-response protocol using
a modified McEliece code-theoretic scheme. Using this method allows combining high resistance to attacks from quantum
computers and optimized use of computing resources. The proposed scheme provides security based on the NP-hard problem
of decoding syndrome, which makes the method resistant to attacks on quantum computers. The implementation of this approach
allows creating more reliable new-generation trunked networks with increased cyber-resistance.
Keywords: trunked radio systems, authentication, code-theoretic schemes, post-quantum cryptography, challengeresponse, P25, OTAR.

References
1. Menezes, A. J., Van Oorschot, P. C., & Vanstone, S. A. (1996). Handbook of applied cryptography
[Електронний ресурс]. CRC Press. Режим доступу: https://cacr.uwaterloo.ca/hac/
2. Shor, P. W. (1994). Algorithms for quantum computation: Discrete logarithms and factoring. In Proceedings
of the 35th Annual Symposium on Foundations of Computer Science (pp. 124–134). IEEE.
3. National Institute of Standards and Technology. (2024). Post-quantum cryptography project [Електронний
ресурс]. Режим доступу: https://csrc.nist.gov/projects/post-quantum-cryptography
4. Alagic, G., et al. (2025). Status report on the fourth round of the NIST post-quantum cryptography
standardization process (NIST IR 8545) [Електронний ресурс]. National Institute of Standards and Technology. Режим
доступу: https://csrc.nist.gov/pubs/ir/8545/final
5. National Institute of Standards and Technology. (2024). Module-lattice-based key-encapsulation mechanism
standard (ML-KEM) (FIPS PUB 203) [Електронний ресурс]. U.S. Department of Commerce. Режим доступу:
https://csrc.nist.gov/pubs/fips/203/final
6. National Institute of Standards and Technology. (2024). Module-lattice-based digital signature standard (MLDSA) (FIPS PUB 204) [Електронний ресурс]. U.S. Department of Commerce. Режим доступу: https://csrc.nist.gov
/pubs/fips/204/final
7. National Institute of Standards and Technology. (2024). Stateless hash-based digital signature standard (SLHDSA) (FIPS PUB 205) [Електронний ресурс]. U.S. Department of Commerce. Режим доступу: https://csrc.nist.gov/
pubs/fips/205/final.
8. Stebila, D., Fluhrer, S., & Gueron, S. (2025). Hybrid key exchange in Transport Layer Security (TLS) 1.3 (RFC
9650) [Електронний ресурс]. Internet Engineering Task Force. Режим доступу: https://www.rfc-editor.org/rfc/rfc9650
9. M. B., Schinzel, J., Lange, T., & Bernstein, D. J. (2025). Hybrid post-quantum key exchange in Secure Shell
(SSH) (RFC 9710) [Електронний ресурс]. Internet Engineering Task Force. Режим доступу: https://www.rfceditor.org/rfc/rfc9710.
10. Cybersecurity and Infrastructure Security Agency. (2024). Link layer authentication and link layer encryption:
Are you really secure? [Електронний ресурс]. Режим доступу: https://www.cisa.gov/sites/default/files/2024-
09/24_0828_s-n_LLA_LLE_are_you_really_secure_2022_final_508C.pdf.