Tesla is working on new key fob with auto unlocking ‘immune to relay attacks’

Tesla is working on a new key fob with auto unlocking and power based on the new UWB technology that is “immune to relay attacks.”

Tesla and relay attacks

Thefts of Tesla vehicles are quite rare in North America, but in Europe, they have some more sophisticated thieves that managed a string of Tesla vehicle thefts through relay attacks, and most vehicles haven’t been recovered.

A relay attack generally consists of using a device that relays the signal from a nearby key fob in order to unlock a vehicle.

In response to those attacks, Tesla started rolling out extra layers of security with an “improved cryptography” key fob and optional “PIN to Drive” feature.

Tesla has since been working to improve its security – even through software updates at the key fob level.

Tesla is now adopting UWB

Now Tesla is looking to add another layer of security.

According to a new filing with the FCC, Tesla is integrating a new single chip Impulse “Radio Ultra Wideband” (IR‐UWB), better known as UWB, inside its new key fob.

Tesla wrote in the new FCC filing:

The main objective of a UWB ranging device is to provide a distance estimate, which serves as a tight upper bound for the actual distance between a sender and a receiver. In other words, the distance estimate is close to the actual distance and may be longer than the actual distance, but not shorter. In the PKE context this means that the key is not further away from the car than the estimated distance. The distance estimate is based on a Time of Flight measurement, and is immune to relay attacks. This drastically improves PHY layer security compared to an RSSI based distance measurement, which is susceptible to relay station attacks.

A UWB receiver can give an accurate distance estimate, when there is a direct line‐of sight (LOS) propagation path between the sender and the receiver. All other propagation paths are caused by reflections, hence have a longer time of flight, and will lead to a looser upper bound for the distance.

Here’s the new Tesla filing in full:

[scribd id=493120588 key=key-Bw9FL0QzA45kIXCLo3nP mode=scroll]

This new technology would be linked to a new key fob, but several phone manufacturers are also adopting it, meaning that it could be implemented to Tesla’s phone key feature.

As we reported last week, Tesla is making its phone app the main key for Model S and Model X with the new updated design, and the app is already the main key for Model 3 and Model Y.