High-speed quantum random number generation for secure data communications

Lead Research Organisation: Heriot-Watt University
Department Name: Sch of Engineering and Physical Science


Random numbers are essential for creating the cryptographic keys that ensure our personal information is secure online. Generating truly random numbers in software alone is impossible, since computers use a completely predictable algorithm for this purpose. Only hardware random number generators can produce true random numbers, and even these are limited by aging effects in classical noise sources. To be truly random one needs a quantum random number generator (RNG), and such devices will be integral to the future of cryptography, forming the basis of secure communications and data processing. Due to their respective technological approaches the clock speeds of commercially available quantum RNGs are limited to few-hundred Mbit/s data streams, a bottleneck that is incompatible with future telecommunications demands.

In this IUK project, which is collaborative with commercial partner Chromacity Ltd., we will demonstrate a route to 100s-of-Gb/s quantum RNG based on novel laser technology. Using a unique high -power green femtosecond laser developed by Chromacity, Heriot-Watt will investigate how amplified parametric downconversion can be used to obtain randomly phased pulse pairs. Vacuum fluctations seed the phases of the downconverted pulses, following which a heterodyne phase comparison yields a random bit stream detectable on a classical fast photodiode. Excitingly, our proposed approach is highly scalable, giving the potential to massively outperform current approaches and enabling the system to keep pace with the demand for high-bit-rate random numbers continues to increase.

Planned Impact

This fellowship will produce immediate industrial and academic impacts, with economic and societal impacts emerging over a longer timescale.

1. Impacts on project researchers
Through the training and development of early-career researchers aligned to the project, the research will support UK industry's need for highly skilled researchers in photonics and quantum technology. Undergraduate students will be engaged with the project at HWU, providing exciting skills development opportunities. Early career researchers will expand their management skills through access to staff development courses, and will extensively develop new professional network contacts in academia and industry.

2. Impacts on academic researchers
This fellowship will generate new scientific and engineering knowledge in the areas of quantum communications and femtosecond laser technology. By disseminating research in peer-reviewed technical journals and conferences, project results will influence the practice of other researchers in areas including quantum random number generation, laser development, and parametric down conversion.

3. Impacts on industry
The proposed research will deliver impact across two main sectors:

(a) Photonics
The development of a high-power source of femtosecond pulses at 520nm will provide exciting opportunities in the development of green-pumped optical parametric oscillators, a technology that could provide tuneable pulses in the 600-1000nm region, a cost-effective alternative to Ti:sapphire lasers and a source with specific potential for CARS microscopy. The development of efficient amplified Yb:fiber lasers is of interest to the manufacturing industry, where the lasers would be ideal seed sources for high-power machining and ablating.

(b) Information systems technology
Random numbers will be required for effective data encryption, and the system targeted in this project will provide a high-speed source of random numbers for future multi-Gb/s telecommunications demands. If the project is successful in demonstrating the potentially massive scalability of the concept to 100s Gb/s random-number generation rates then the impact on practice in both quantum and classical optical communications would be profound transformative.

In both the photonics and information systems domains there is significant potential for generating new and protectable intellectual property, which would provide the security for SMEs such as Chromacity to invest in and exploit the technology for the benefit to their businesses and shareholders but also to the UK in general.


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Description Strategic Agreement with Chromacity Ltd 
Organisation Chromacity Ltd
Country United Kingdom 
Sector Private 
PI Contribution This Innovate UK award was the founding grant for my research group. This grant has enabled the formation of a strategic agreement between my group and Chromacity Ltd, providing Chromacity with the right of first refusal of IP generated in my laboratory, as Chromacity are the primary exploitation partner for much of my planned research in the next 5 years.
Collaborator Contribution Chromacity have provided my laboratory with a Yb:fiber laser and external frequency doubling module with an associated cash value of £20,000. This laser source will be used for proof-of-concept studies that will form the basis of future grant applications.
Impact No outputs have arisen from this collaboration as of February 2019.
Start Year 2018