A significant breakthrough in quantum optics by a collaborative team from the Universities of Glasgow and Strathclyde is offering new encryption possibilities for security agencies to limit eavesdropping and offer sophisticated covert communication techniques. A related ability to increase the amount of information that can be carried by beams of light is also being evaluated.

Collaborating under the Synergy Programme and with projects funded through the Scottish Enterprise's Proof of Concept Fund and EPSRC (The Engineering and Physical Sciences Research Council), the team's approach uses a strange property of light called "orbital angular momentum".

Photons, single particles of light, have long been known to spin but they can also twist. This movement is known as their orbital angular momentum. Light beams carrying this OAM can be transmitted to receivers where the information can then be decoded ﾖ effectively the 'twists' need to be untwisted in order to decipher the full message.

Significantly, the team's new method can more effectively identify if an attempt has been made to intercept the message as it would 'break' the beam.

As Steve Barnett from the University of Strathclyde comments, "Sometimes it can be just as important to know if someone is trying to listen to your communications so an effective method to detect intervention would be important to security agencies."

Miles Padgett, University of Glasgow, continued, "Because the full beam has to be decoded in its entirety, it would be virtually impossible to read the information from scattered light alone. In other words, it wouldn't mean anything if you only 'eavesdropped' into a scattered segment of it. It needs to be all or nothing. That means it could provide an inherent level of security that would keep both 007 and 'M' happy!"

The practical application of this theory is currently being put to the test through the development at the University of Glasgow of a demonstrator unit designed by Dr Graham Gibson of the collaborative optics team, their very own 'Q'.

He explains, " I envisage that the ongoing development of this system will be very much guided by the feedback that we will get from potential market sectors, particularly the security sector. We need to identify what matters most to them and maximise the technology's capabilities in these key areas."

The demonstrator unit has already proven an associated feature of Orbital Angular Momentum ﾖ the ability to increase the communication bandwidth of Free Space Optics systems. It is now allowing the related security features to be developed and evaluated.

For further information on the project please contact Don Whiteford (Tel: 0141 330 2728, e-mail: d.whiteford@enterprise.gla.ac.uk)

Media Relations Office (media@gla.ac.uk)

The Proof of Concept Fund supports leading-edge technologies emerging from Scotland?s universities, research institutes and NHS Trusts. It helps researchers to develop their ideas and inventions from the lab to the global marketplace.

Launched in 1999 with initial funding of ?11 million for three years, the Fund has now been trebled to ?33 million over a six-year period; it is currently supporting 120 groundbreaking projects worth around ?19 million.

Synergy is a strategic alliance between the University of Glasgow and the University of Strathclyde.This alliance creates one of the UK's largest knowledge bases with research strengths extending from the Arts and Humanities, Social, Biological and Physical Sciences to Computing, Statistics and Engineering and the professions of Law, Business and Medicine (both human and veterinary).

The combined research funding portfolio of the two universities is in the order of ?100M per annum.

First published: 26 January 2004