End-to-end Quantum Secured Inter-Domain 5G Service Orchestration Over Dynamically Switched Flex-Grid Optical Networks Enabled by a q-ROADM

Dynamic and flexible optical networking combined with virtualization and softwarisation enabled by Network Func- tion Virtualization (NFV) and Software Defined Networking (SDN) are the key technology enablers for supporting the dynamicity, bandwidth and latency requirements of emerging 5G network services. To achieve the end-to-end connectivity objective of 5G, Network Services (NSes) must be often deployed transparently over multiple administrative and technological domains. Such scenario often presents security risks since a typical NS may comprise a chain of network functions, each executed in different remote locations, and tampering within the network infrastructure may compromise their communication. To avoid such threats, Quantum Key Distribution (QKD) has been identified and proposed as a future-proof method immune to any algorithmic cryptanalysis based on fundamental quantum- physics mechanisms to distribute symmetric keys. The maturity of QKD has enabled the research and development of quan- tum networks with gradual co-existence with classical optical networks using carrier-grade telecom equipment. This makes the QKD technology a suitable candidate for security of distributed and virtualised network services.