ITU adopts first international standard covering quantum key distribution protocols

The International Telecommunication Union (ITU) has published its first international standard dedicated to quantum key distribution (QKD) protocols, providing a common framework for securing communications as quantum technologies challenge existing cryptographic methods.

The new standard, ITU-T Recommendation X.1711, Framework of QKD protocols in QKD networks, does not prescribe a single protocol. Instead, it identifies common features across QKD protocols, outlines the architecture they require and describes operational workflows. It also covers theoretical security proofs and security models relevant to their implementation.

QKD enables two parties to establish shared encryption keys using quantum-based methods. As organisations explore its use in communications networks, common technical standards can help establish consistent approaches to security and certification. X.1711 is intended to serve as a reference for assessing and selecting certified QKD modules, as well as informing the development of future standards.

The recommendation was developed by ITU-T Study Group 17, which focuses on security. It forms part of the ITU’s broader work on QKD networking, which has been under way since 2018. Other groups address related aspects: Study Group 11 works on protocols and testing, while Study Group 13 focuses on network architecture.

The work is also connected to deployments and testing initiatives. Singapore’s National Quantum-Safe Network Testbed, for example, collaborates with Study Group 17 on QKD standardisation. The ITU has also highlighted satellite-based QKD as an area of development, with work under way on network architecture and security considerations for extending key distribution over long distances.

The ITU’s approach sits alongside related standardisation efforts by other organisations. The European Telecommunications Standards Institute (ETSI) has developed a protection profile for QKD modules, while the International Organization for Standardization and the International Electrotechnical Commission have jointly developed standards covering security requirements and testing and evaluation methods for QKD.

As different organisations develop standards for quantum communications, the ITU maintains a public database of quantum standards through its standards landscape tool. Recommendation X.1711 adds a shared framework to this work, with the aim of supporting security assessment and interoperability as QKD moves towards broader deployment.