Beyond CCTV: the serious science of surveillance

Monitoring is becoming ever more advanced, Rob Hastings finds

As a world-leading expert in developing biometric techniques to identify people using CCTV, Professor Mark Nixon has "had a few fights" with civil liberties groups in his time.

Through his work at the School of Electronics and Computer Science at Southampton University, which is funded by the likes of the Pentagon and the Ministry of Defence, it is becoming increasingly easy for authorities to monitor us all.

Now Prof Nixon's department has received extra funding from GCHQ to form part of the national Cyber Security Centre of Excellence, with Southampton specialising in biometrics: ID-ing people using personal traits or physical characteristics.

One of the key aspects is gait analysis: allowing people to be identified by their body shape and the way they walk. It has helped solve several crimes in Britain, and in Sweden it helped convict the killer of foreign minister Anna Lindh in 2003.

The potential of such surveillance systems is enormous. But so too, warn campaigners, are the privacy risks. This year the Government's first Surveillance Commissioner, Andrew Rennison, said there was a worrying lack of regulation over the use of CCTV; human rights laws risked being broken, he added.

But Prof Nixon says his techniques "have been used to put murderers away – and I agree with that. Privacy concern has a long history. If you read into the history of maps, people didn't want the cheeky bastards making maps of their land. People are always suspicious of what they don't know, but most people would say they don't mind the police knowing if they can eliminate a serious threat."

His research into facial recognition, which turns the measurements of someone's facial features into a series of numbers to be matched against a database by a computer, has helped make it a viable technique – one that was used after the 2011 London riots in an attempt to catch looters and those breaking the law in other ways.

And as Prof Nixon says: "Your identity is manifest in many different ways. Ears, eyes, foot steps – all can be used to identify people. Even your heartbeat can betray who you are, and it can be detected from a distance without requiring contact with the body."

For those wearing masks or scarves over their faces, there are still plenty of ways computers can identify them. Much of the research has been carried out in the "biometrics tunnel" built in Prof Nixon's department.

As I wander down it, eight cameras film my strides from a variety of angles against multicolour backgrounds, allowing electronic silhouettes and a 3D virtual model of my body to be constructed by a computer. The distances between my feet, knees, hips, shoulders and head are measured and the pattern of their motion analysed. If I were a suspect, police would be able to compare my gait profile to information gathered from CCTV – either eliminating me from their enquiries or using the results to delve deeper.

Some of the work in the new centre will go into online identification. Keystroke analysis, looking at the minute differences in timings and patterns between different computer users' typing mannerisms, is another pioneering technique under development.