A simple form of cyber attack which can easily be mastered by teenage hackers could bring railway networks to a standstill, a security expert has warned.
Anyone who knows how to unleash a "denial of service" attack could cause such disruptions in major rail networks around the world, said to Stefan Katzenbeisser, professor at Technische Universitat Darmstadt in Germany.
The vulnerability, he pinpointed, is due to mobile phone signals used to link railway switching systems together that would allow hackers to cause massive service disruption.
"Denial of service" campaigns are one of the simplest forms of cyber attack, where hackers recruit large numbers of computers to overwhelm the targeted system with Internet traffic, Prof Katzenbeisser said.
The attacks, he said, require less skill than penetrating a computer network or writing malicious software and hackers have used the approach to attack sites of government agencies around the world and sites of businesses, Daily Mail reported.
"Trains could not crash, but service could be disrupted for quite some time," said Katzenbeisser.
According to Prof Katzenbeisser, train switching systems, which enable trains to be guided from one track to another at a railway junction, have historically been separate from the online world, but communication between trains and switches is handled increasingly using wireless technology.
The use of "connected" systems renders them vulnerable to cyber attack, he claimed.