Flexible and Dynamic Secure Key Allocation in a Programmable Quantum Key Distribution Network

Quantum key distribution (QKD) allows the secure transmission of encryption keys to guarantee secrecy even in the coming age of quantum computers. However, the integration of QKD within deployed fiber networks remains challenging. To this end, we present a programmable QKD network scheme which allows for flexible secure key-rate allocation between users: by equipping each user with the same broadband monolithic silicon-photonic quantum transmitter and subsequent channel definition through wavelength slicing as well as flexible detector allocation we achieve a dynamic secure-key rate range of 18.7 dB (76x). Further simulations confirm that this approach enables a fine-grained and efficient use of network resources to allow a fair and dynamic distribution of secure keys between users.