Engineering news

Faster secure data transfer

PhD student in Engineering Lucian Comandar is the lead author on exciting new research in the journal Nature Photonics that points the way to transferring secure information at much faster rates than previously observed.

Conventional communication security relies on the assumption that a potential hacker is limited in terms of the computing power; but the industry is concerned that  developing technologies will be able in the future to break traditional encryption.  This creates an important practical need for unbreakable secure communication.

Scientists have for some time worked using quantum techniques models of encryption and data transfer, but research has stumbled over how best to securely transfer an encryption key needed for a recipient computer to decode the data being transferred. 

The research team from the University of Cambridge, which included Master of Sidney Professor Richard Penty, and Toshiba Research Europe has been testing so-called quantum key distribution protocols (QKDs), investigating the use of photons (or beams of light) for key encryption.  The team used a protocol that requires the interference of indistinguishable photons from different sources at high rates.  The interference outcome is used as security mechanism to then regulate the transfer of an encryption code. 

The team developed a special technique involving the use of short pulses of laser beams, specially ‘seeded’ one inside another, to overcome a problem of timing jitter that had previously limited the production of indistinguishable photons.  Being able to control and change the timing of the pulses rapidly also provides an enhanced level of security.  The new technique – named pulsed laser seeding – could see transfer rates of 1 megabit per second, an improvement of two to six orders of magnitude compared to previous observed research.

You can read more about the research by visiting the University of Cambridge’s Research News website.

Reference: L.C. Comandar et al. (2016) Quantum key distribution without detector vulnerabilities using optically seeded lasers. Nature Photonics DOI: 10.1038/nphoton.2016.50

For further information please contact the Fellow Communications Officer, Dr Tom Lambert (

This is an archived news story first posted in April, 2016