The Engineering of a Scalable Multi-Site Communications System Utilizing Quantum Key Distribution (QKD)

Abstract

Quantum Key Distribution (QKD) is a means of generating keys between a pair of computing hosts that is theoretically secure against cryptanalysis, even by a quantum computer. Although there is much active research into improving the QKD technology itself, there is still significant work to be done to apply engineering methodology and determine how it can be practically built to scale within an enterprise IT environment. Significant challenges exist in building a practical key management service for use in a metropolitan network. QKD is generally a point-to-point technique only and is subject to steep performance constraints. The integration of QKD into enterpriselevel computing has been researched, to enable quantum-safe communication. A novel method for constructing a key management service is presented that allows arbitrary computing hosts on one site to establish multiple secure communication sessions with the hosts of another site. A key exchange protocol is proposed where symmetric private keys are granted to hosts while satisfying the scalability needs of an enterprise population of users. The key management service operates within a layered architectural style that is able to interoperate with various underlying QKD implementations. Variable levels of security for the host population are enforced through a policy engine. A network layer provides key generation across a network of nodes connected by quantum links. Scheduling and routing functionality allows quantum key material to be relayed across trusted nodes. Optimizations are performed to match the real-time host demand for key material with the capacity afforded by the infrastructure. The result is a flexible and scalable architecture that is suitable for enterprise use and independent of any specific QKD technology.

Quantum Key Distribution

“…Considering the efforts to extend the QKD network to metropolitan areas, which involves a significant number of network nodes, a hierarchical organization was considered in previously implemented networks [42,125,[149][150][151]. This approach, which is based on a key management layer, converges to a software-based network paradigm and is discussed in more detail in Section 7.…”

QUARC: Quantum Research Cubesat—A Constellation for Quantum Communication

“…Trusted node SatQKD can be realised using the spacecraft as a receiver (uplink (UL) configuration) or as a transmitter (downlink (DL) configuration). A DL configuration requires the development of a space-qualified optical assembly for precise pointing of the order of few µrad and quantum sources driven by quantum random number generators [38,39]. The UL configuration requires a less complicated payload comprising single photon detectors but would also require a larger telescope compared to DL [36,47].…”

“…On the other hand, Small Satellites (SmallSats) and especially the popular CubeSat standard have been in the spotlight for their potential to deliver meaningful communication volumes at a significantly reduced price and complexity. Operationally, they represent a path finder option for the deployment of large constellations offering rapid revisit and therefore greater coverage than a single large spacecraft [38,39].…”

Quantum key distribution integration with optical dense wavelength division multiplexing: a review

“…The trusted node combines (e.g. by using XOR function) these separate keys to form an end-to-end key between node [21][22][23].…”