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NPL’s quantum capabilities for industry

Securing communications with single photons

Analysing discrete-variable Quantum Key Distribution hardware

Quantum Key Distribution (QKD) revolutionises cryptographic key establishment. It utilises the transmission and detection of photons (quanta of light), alongside conventional measurement data, to generate an unbreakable key. 

QKD's exceptional strength lies in its guaranteed security, independent of an eavesdropper's resources or computational power. This ensures perfectly secure cryptographic key transmission, even over channels compromised by adversaries. 

The main customers for QKD metrology are the developers and manufacturers of QKD systems, along with the organisations deploying them for secure communication. QKD metrology equips system builders with the tools to ensure their creations meet rigorous security standards and function optimally. For deploying organisations, like government agencies and financial institutions, QKD metrology verifies the trustworthiness and effectiveness of their deployed systems, guaranteeing ultra-secure communication. 

Metrology for QKD systems is critical for reliable, secure information transfer and encryption. The National Physical Laboratory (NPL) develops metrological techniques for discrete variable QKD, focused on the accuracy and precision of underlying systems and devices. This meticulous approach safeguards the integrity of quantum-based communication. 

NPL's key metrological support: 

  • Quantum Bit Error Rate (QBER) estimation: Measures discrepancies within raw keys, with high QBERs indicating interference. This involves key comparisons and error correction. 
  • Photon Statistics Characterisation: Determines photon count per pulse (crucial for security analysis), especially when using attenuated lasers, to mitigate risks like Photon Number Splitting (PNS) attacks. 
  • Detector Efficiency and Characterisation: Assesses a detector's registration accuracy, including wavelength-dependent efficiency, dark count rates, afterpulsing probabilities, and timing jitter. This data is vital for key rate calculations and security assessments. 
  • Channel Loss and Noise Characterisation: Measures quantum channel efficiency (e.g., optical fibre) and background noise (stray light, dark counts), directly affecting achievable distance and key rate. 

For further information on our QKD support, please contact us.

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