Future-Proofing Industrial Protocol Security: Integration of Post-quantum Cryptography in the Modbus Protocol

This paper investigates the integration of Post-quantum Cryptography (PQC) into the Modbus TCP Security protocol, a cornerstone in İndustrial Control Systems (ICS), against the backdrop of the emerging quantum computing era. Recognizing the vulnerability of conventional cryptographic methods to quantum computing, particularly asymmetric algorithms like RSA and ECC, we explore PQC's potential to bolster security in ICS. Employing a precise methodology to measure Modbus connection times, we analyze various cryptographic configurations, including classical algorithms, standalone PQC, and hybrid PQC systems. Our results indicate a significant reduction in connection times with PQC, especially with Dilithium certificates, compared to traditional ECC-256 and RSA-2048 methods. The study also highlights the trade-offs in security and performance, particularly in configurations with and without Transport Layer Security (TLS). This research serves as a reference for future explorations in more realistic industrial scenarios, emphasizing the necessity of transitioning to PQC to safeguard ICS in the quantum computing age.