Research Stories

Collaborative research including Acting Master Richard Penty may help reduce the cost of long distance cable transfers of secure data.

In a paper published in Physical Review X, a team of scientists from Toshiba Research Europe and Cambridge University’s Department of Engineering outline a new development in secure data transfer over long distance fibre optic cables.

The research, reported recently in the New York Times, BBC and Sydney Morning Herald, marks an advance on a technique of secure data transfer known as Quantum Key Distribution (QKD).  Formerly, the secure QKD channel has only been transmitted over long distances on its own. But this has been liable to photon noise contamination, which can limit or destroy the performance of QKD if operating over long distances. 

The team’s research has shown for the first time that this secure QKD channel can be transmitted at the same time as multiple high bandwidth ‘normal’ (or classical) channels.  The lead author on the research paper is Professor Penty’s PhD student Ketaki Patel and Professor Penty provided input on how to maximise the performance of these classical channels. 

This new technique may help pave the way for high bit-rate secure data communications along single fibres of lengths of up to 90km.

This is an archived news story, first posted in 2012.

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

News item posted Sunday, 3rd May 2015

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