In the self-driving car business, decisions are only as good as your sensor data. While the state-of-the-art Velodyne LIDAR that adorns benchmark research vehicles will set you back $80,000, winning the DARPA urban challenge probably requires the better part of a cool million. Unfortunately, all it may take to spoof sophisticated sensors like these is a cheap laser pointer pulsed by something as simple as an Arduino or Raspberry Pi.
As IEEE Spectrum reports, security specialist Jonathan Petit will be presenting a disturbingly easy new hack this November at the Black Hat Europe conference. After recording the probe signals from an IBEO Lux lidar unit, Petit simply fired them back at the emitter using his laser. As long as they were synchronized, the lidar unit ‘saw’ an illusory object in front of it. The trick works up to 100 meters away in any direction — at the front, back or side — and doesn’t even require a tightly focused beam.
Although other hacks like spoofing the vehicle’s GPS or tire sensors have been done before, Petit’s hack could potentially bring a vehicle at speed to a full stop. Several 3D-rendered vehicles could be placed not only in front of the car, but actively moving toward it. That would present quite a gauntlet to any control now on the market.
Lidar systems don’t operate in a radiation band that is licensed like short-range radar. Nor do they typically encode or encrypt their pulses. These realities makes them particularly vulnerable to anyone deliberately targeting them. But lidar systems are evolving rapidly, becoming not just cheaper, but more capable. So-called ‘sensor-fusion’ technology is also evolving to the point where hacking just a single sensor, or a single kind of sensor, may not be enough to overwhelm the system.
For example, last week a radically new kid of was laser systen in Scientific Reportsthat combines an electrically-pumped vertical-cavity surface-emitting laser (VCSEL) with a micromechanical resonator on a single chip. This device would be able to sweep the output beam across a broad wavelength band in a microsecond (as opposed to 10 milliseconds) to create a highly efficient LIDAR source beam. Putting the wavelength control functions inside the laser itself in this way would mean tiny, fast, and low-power sensors at a fraction of the cost.