Car hacking is not a new field, but its secrets have long been closely guarded.

That is about to change, thanks to two well-known computer software hackers who got bored finding bugs in software from Microsoft and Apple.

Charlie Miller and Chris Valasek say they will publish blueprints of techniques for attacking critical systems in the Toyota Prius and Ford Escape, following several months of research.

The two "white hats" – hackers who try to uncover software vulnerabilities before criminals can exploit them – will also release the software they built for hacking the cars at the Def Con hacking convention in Las Vegas this week.

They said they devised ways to force a Toyota Prius to brake suddenly at 80 miles an hour, jerk its steering wheel, or accelerate. They say they can disable the brakes of a Ford Escape travelling at very slow speeds.

But, the two scientists were sitting inside the cars using laptops connected directly to the vehicles' computer networks when they did their work. So they will not be providing information on how to hack remotely into a car network.

The two say they hope the data they publish will encourage other white-hat hackers to uncover more security flaws in vehicles so they can be fixed.