Improving data security with quantum technology: Guaranteeing the security of sensitive data
Quantum communication technologies such as quantum key distribution (QKD) can improve the security of the ever-increasing amount of sensitive information that is stored, transferred and accessed over computer networks. The unique feature of QKD is that, when implemented correctly, the system guarantees that the encryption key has not been intercepted. In theory, it is extremely effective but there are no agreed methods to demonstrate that practical implementations are robust. The main challenge is the identification of the physical system parameters critical to QKD and the development of appropriate metrics and measurement techniques for their quantification, in particular the properties of quantum sources, channels and receivers.
This project developed:
- Techniques for traceable characterisation of photon sources with unknown quantum states including methods for measuring the mean photon number at communications wavelengths traceable to the SI, a novel photon-number-resolving (PNR) detector capable of measuring more than one photon in a pulse, a high-resolution, high-transmission fibre-coupled single-photon spectrometer suitable for spectral analysis of pulsed sources at communications wavelengths and an optimised single-photon source as a reference for quantum sources.
- Tools for traceable characterisation of quantum channels for optical fibre-based communication systems including development of ‘open system’ quantum random number generators – an essential tool in encryption and the development of a single-photon polarimeter for reconstructing the polarisation state of a single photon transmitted down an optical fibre – used to measure system noise using conventional light levels transmitted via a standard communication fibre optic link.
- Methods for traceable characterisation of single-photon detectors including characterisation methods for determining parameters and properties of commercially-available single-photon detectors and a calibrated attenuator to simplify detector characterisation and determine quantum efficiency with an uncertainty of less than 3 %.
The project put in place a series of measurement systems that characterise the properties of individual particles of light, as well as QKD technologies, and has laid the foundations for a European measurement infrastructure able to validate the performance of QKD systems to support the development of next-generation communication systems and quantum networks. The project provided important metrological expertise to support a real-world demonstration, led by industry, of well-characterised QKD over a single field-installed lit fibre. This work makes QKD a more attractive commercial proposition and will accelerate its commercial deployment.
- EMRP Industry theme impact case studies
- News: Invited talk at Quantum UK 2016
PHYSICAL REVIEW A
Proc. SPIE 9136, Nonlinear Optics and Its Applications VIII; and Quantum Optics III
International Journal of Quantum Information
Physical Society of Japan
Physical Review A
Foundations of Physics
Quantum Electronics, IEEE Journal of
SPIE 8773, Photon Counting Applications IV; and Quantum Optics and Quantum Information Transfer and Processing
Proc. SPIE 8875, Quantum Communications and Quantum Imaging XI
Proc. SPIE 8899, Emerging Technologies in Security and Defence; and Quantum Security II; and Unmanned Sensor Systems X
Physical Society of Japan
Laser Physics Letters
Proc. SPIE 8542, Electro-Optical Remote Sensing, Photonic Technologies, and Applications VI
Applied Physics Letters
Physical Review Letters