Summary - Y.3835 (04/2026) - Integration of quantum key distribution networks and user networks supporting end-to-end modern cryptography services – Functional architecture for quality-of-service assurance

Recommendation ITU-T Y.3835 specifies functional architecture, associated capabilities, reference points, and an operational procedure of quality-of-service (QoS) assurance for integrated quantum key distribution network (QKDN) and user network supporting end-to-end modern cryptography (UNemc) based on the defined reference models and requirements in Recommendation ITU-T Y.3828.
It is challenging to integrate a QKDN and a user network to support end-to-end modern cryptography services to users including mobile objects (i.e., autonomous car, mobile phone, etc.). Supplement 79 to ITU-T Y.3800-series Recommendations addresses this issue and describes several use cases to deliver KSA-keys generated from QKDNs to the user applications by means of modern cryptography (e.g., PKI technology) with post quantum cryptography (PQC) algorithms. It also identifies various issues to be addressed for standardization. Technical implications from the three end-to-end use cases identified are related to control and management, and QoS aspects. Especially, Recommendation ITUT Y.3828 addresses QoS assurance specific aspects in terms of reference models and requirements.