Metrology for testing the implementation security of quantum key distribution hardware

The security of personal and commercial data has never been more valued. Today, most digital infrastructures are secured by cryptographic keys, but advances in quantum computing herald new threats. Long term, the best protection may be provided by Quantum Key Distribution (QKD), a communication approach designed to ensure privacy using quantum information encoded in light signals. In theory, QKD can be proven as secure. In practice, devices implementing the technologies do not always follow this ideal behaviour. The earlier EMPIR MIQC2 project developed methods to characterise single QKD component technologies, that were incorporated into European Telecommunications Standards Institute (ETSI) specifications. Further security testing methods are now needed for characterising complete QKD devices, as well as tests to uncover vulnerabilities and to measure the effectiveness of countermeasures to attacks. Test methods suited to new types of light detectors are also needed.

The project has developed new measurement methods for characterising complete QKD systems (with combined transmitter and receiver modules), and for other QKD technologies requested for development by ETSI. Tests and security standards have also been devised to uncover hardware vulnerabilities in real systems. Methods to characterise QKD modules and free-space detectors were also developed. The resulting standardised methods will support the commercialisation of novel devices. Ultimately, a comprehensive range of standards could form the foundation of a certification scheme that should encourage additional investments in research and help provide assurance to the public in the security of QKD systems.