Principal Scientist at Security Innovation, Jonathan Petit, will be presenting a paper on how to trick Lidar sensors which are normally found in self driving cars at the Black Hat Europe security conference in November 2015 as reported at IEEE Spectrum. He claimed that he was able to trick the sensor into seeing things which are not actually there using low power laser and pulse generator. Light Detection and Ranging (Lidar) is actually radar like system which uses pulsed lasers to create a 3D image of the world. It is basically the eye of a self driving car.
It can be done by recording pulses from an off-the-shelf Lidar, an Ibeo Lux and played it back by a laser and a pulse generator, making Lux see things which are actually not there. It works within 100 meters distance and can be carried out from the front, back and side of the Lux unit.
The attack would cause a self driving car to slow down or drive erratically or even could overwhelmed the system and thus creating a denial-of-service attack which eventually cause the car to stop moving entirely. The attack is currently working only on Ibeo Lux and it does not mean that Lux is bad but Petit thought maybe the companies which build Lidar units have not thought about the possibility of this attack.
Petit was based at University College Cork, Ireland when he did this experiment.