QKD in the use case of supervisory control and data acquisition (SCADA) systems: Using the example of hydropower plants

Quantum computing promises significant computational speed-ups that could compromise the security of current public-key cryptography. As quantum technologies advance, SCADA systems willincreasingly require enhanced cybersecurity measures. Two main quantum-safe approaches exist:
Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD). QKD offers the unique advantage of information-theoretic security, ensuring security regardless of an adversary’s computational power. This thesis addresses two identified research gaps: protecting SCADA networks against
potential quantum-computer-based attacks and identifying relevant use cases for QKD to guide further research and adoption. The objective was to assess whether QKD is a viable solution for securing SCADA communications in hydropower plants against quantum threats. The analysis included
designing a QKD-based SCADA communication architecture for a hydropower network, conducting a quantum vulnerability assessment, simulating the proposed setup and evaluating the advantages and disadvantages of QKD migration. The results indicate that, at the time of writing, QKD is not a viable
option for securing SCADA communications in hydropower plants, as its disadvantages outweigh its benefits. For instance, QKD cannot guarantee availability, which is a critical requirement for SCADA in many critical infrastructures, including hydropower, and it is more costly than alternative quantumsafe solutions.