In February 2019, the European Telecommunications Standards Institute (ETSI) Industry Specification Group on Quantum Key Distribution (ISG QKD) published Group Specification GS QKD 014, defining a REST-based application programming interface (API) for key delivery from QKD networks to applications. The specification described a communication protocol and data format intended to allow interoperability of QKD equipment and applications from different vendors.
GS QKD 014 specified the format of URIs, the HTTPS communication protocol, and JavaScript Object Notation (JSON) data format encoding. The standard was developed based on a proposal from Toshiba and provided a simpler alternative to the earlier ETSI GS QKD 004 application interface, using a REST-based approach familiar to a large developer community.
The standard has since been widely adopted by QKD system vendors and classical encryptor manufacturers for integrating quantum key distribution into telecommunications networks. It has served as a reference interface for QKD network deployments globally.