Industrial Strategy Challenge Fund projects

Producing miniature atomic clocks

The £7M ISCF project KAIROS, which began in November 2018, concluded in 2021. Led by Teledyne-e2v, it successfully developed pre-production miniature atomic clock prototypes, named MINACTM. The MINAC™ started its journey at NPL as a TRL 4 demonstrator in 2016. Since then, NPL have been working closely with Teledyne-e2v to transfer the technology and assist them with establishing manufacturing capabilities at their site in Essex, to produce the miniature atomic clocks. 

NPL also helped to establish new wholly UK-based supply chains for key components used in MINAC™, including state-of-the-art single-mode vertical cavity surface emitting laser (VCSEL) diodes and best-in-class oven-controlled crystal oscillators (OCXO), which are also crucial components used in a wide variety of commercial and defence applications. The MINAC™ clocks are designed to provide precise timing to a variety of critical infrastructure services, such as energy supply, transport links, mobile communications, data networks and electronic financial transactions. The MINAC™ outperforms the nearest competitor clocks with respect to phase noise and short-term stability.

Validating quantum random number generators

Quantum random number generators (QRNGs) use the inherent randomness of natural physical processes to create their output. This is an underpinning technology for creating uncrackable quantum encryption keys. However, there is currently no method for certifying the unique randomness produced by QRNGs.  Modelling and experimentally testing the physical process used to create a QRNG’s output can be used to evidence its quantum nature, and hence its uniqueness. The AQuRand project, led by NPL, is developing expertise and capability to do this validation, and inform regulation. We are setting up a consortium, establishing a test facility and NPL and testing vendor QRNG prototypes, and participating in standards development processes.

Enabling QKD over-the-air

Whilst much quantum communications happens in fibre, at the user end, encoded particles may need to make the short journeys from the end of the network to the user’s device.  AirQKD is establishing a UK ecosystem – from single-photon components to networked quantum systems – to develop short to mid-range communication in free space. This will include pilot demonstrations of enabling infrastructure for quantum-secure 5G and autonomous and connected vehicles.

In this collaborative project, NPL leads work on security evaluation of free-space QKD hardware and the characterisation of QKD components (receivers and transmitters and quantum random number generators) through establishing testing facilities, models and processes.

Validating secure key distribution technologies

Future secure communications, that cannot be cracked by quantum computers, will combine QKD and quantum-resistant algorithms. This involves a wide range of new technologies to create and distribute secure keys. The AQuaSeC project developed supply chain components, built prototypes, tested their security and demonstrated their benefits to end users. From this testing, NPL developed QKD security accreditation process and documentation.

QKD in space

QKD is limited by absorption inside optical fibres which mean that transmissions over distances greater than about 150 km are impractical. Free space communication does not suffer the same attenuation. Single photon communication using satellites orbiting the Earth has been demonstrated and could provide an ideal vehicle for distributing quantum key information across continents.

Satellite QKD will need a network of Optical Ground Receivers (OGRs) to receive and detect the encoded photons. The UK, as a major player in the development of advanced optical and photonic technologies, is well positioned to address this future market.

The Space3QN project is working with users to specify OGR requirements, and to prototype and test a QKD receiver, whilst designing and making plans for scaled manufacture in the UK. Within the project, partners built modular QKD prototype receivers, in collaboration with end users in critical sectors. NPL provided testing and verification of quantum specific elements. As a result of the project learnings, we will soon launch a commercial measurement service for detector  characterisation.

Strengthening the weak links in space based QKD

QKD is only as secure as its least secure system element. Space-based QKD components presents new challenges because the onboard quantum processing chain is an attractive attack route. Challenges in securely engineering quantum technology relating to system remoteness, space environment, delivery platform and classical communication channels must therefore be overcome before adoption.

The PRISMS project assessed potential attack routes on QKD systems and provide a bench top demonstration of a fully tested system aligned to relevant standards. The quantum elements of the programme will be the implementation of a quantum random number generator and quantum protocol processing algorithms on representative space hardware. NPL delivered software to Craft Prospect (who run the test bench) which used statistical tests to RNGs and undertook a stringent pre-assessment of two QRNG units, implemented software to, and completed a prototype implementation of a neural network model for identifying non-randomness.