A team of Chinese maths' enthusiasts has thrown a speed camera system in Australia into disarray by cracking the technology used to store data about errant motorists.
A motorist's defence lawyer there argued successfully that an algorithm known as MD5, which is used to store the time, date, place, number plate and speed of cars caught on camera, was discredited technology.
MD5 is one of many types of encryption used by programmers to safeguard all kinds of data when it's being transferred or stored.
Australia's digital speed cameras capture an image as soon as a speed violation occurs, recording the time, place, number plate and speed onto the image. The image is encrypted in a matter of milliseconds and imprinted with a unique MD5 code at the top to prevent tampering or highlighting.
Changing even one pixel in the input file is supposed to change the encryption code, proving that an image was doctored after it was taken. Last year, researchers from China's Shandong University proved it was possible to store conflicting pieces of information as the same MD5 sequence - that is alter the data and retain the same encryption code, thereby failing to prove tampering.
Nick Ellsmore, an encryption expert at the consultancy SIFT, said this theoretically meant the New South Wales Road Traffic Authority could change the speed at which a car was recorded and retain the same code.
The case went to court in June and the authority was asked to prove its photos of the alleged speeding violation had not been doctored. Last week, its lawyers said they could not find an expert to prove the authenticity of the mathematical algorithms on each picture or to testify that its digital speed camera images could not have been tampered with. The case was dismissed and the motorist awarded costs.
A spokesman for the authority rejected the decision as a one-off, indicating time was a factor but it would continue to defend such cases, as it was confident the algorithm system was tamper-proof, according to Australia's AAP news service. The 110 cameras in New South Wales pull in more than €623,000 (1 million Australian dollars) a week.
Speed cameras in Ireland use old-style film to record cars travelling over speed limits. One roll of film photographs about 400 violations and is then processed.
Legislation due in October is set to privatise the operation of cameras and the units and the system to view images will be managed by a private operator.
The Working Group on Safety Cameras recently said it was more efficient to transfer the risk of advances in technology to a private operator and the Department of Justice is due to put the business to tender.
Privatisation may lead to use of digital cameras which are very cost-effective and efficient at storing and transferring images back to base.
Sources in the industry here believe that last week's Australian case is unlikely to be open season for speeding motorists in countries using digital cameras, saying that systems are very secure - but, like DNA, it was very hard to say 100 per cent that it was right.
"It was the encryption method that was called into question, not the digital technology," says John Lane, manager of the ITS division of Dublin-based Electro Automation. "There are many methods of securing data such as Triple DES, used in British Home-Office approved equipment supplied by us." Triple DES is also used in Germany and Scandanavia.
"Difficulties will not be with the encryption," says Joe Carthy, senior lecturer at UCD's Computer Science Department.
"As regards 'John Citizen' caught speeding, even if he is an advanced encryption analyst, to try to hack into a system, isolate an image, interfere with it, especially in the nanosecond during transmission, it's really next to impossible even with MD5. But companies will need to have secure computing systems and trusted personnel."