The recently revealed vulnerability enabling hackers to trivially duplicate Tesla Model S key fobs, in my mind prompts an interesting technology question.
The Hack in a Nutshell
This does not apply to all Model S vehicles, but in simple terms, using a few hundred dollars of off-the-shelf radio and computer hardware, malicious actors can intercept transmissions from your key fob when nearby.
Using the intercepted data and about two seconds of computational power, they are able to duplicate your key fob.
This allows them to open your Tesla Model S, start your Tesla Model S, and drive your Tesla Model S away.
Noting that the cryptographic keys in use are only 40-bit keys, quoting from the Wired article:
The researchers found that once they gained two codes from any given key fob, they could simply try every possible cryptographic key until they found the one that unlocked the car. They then computed all the possible keys for any combination of code pairs to create a massive, 6-terabyte table of pre-computed keys. With that table and those two codes, the hackers say they can look up the correct cryptographic key to spoof any key fob in just 1.6 seconds.
The High-Tech Solution
To solve this vulnerability, Tesla are recommending a firmware update to the security systems in the Model S.
After unlocking the car and disabling the immobiliser system with the key fob, drivers would now need to enter a PIN on the console of the car before they can start it.
This provides rudimentary two-factor authentication, and is probably a reasonable solution to the problem, albeit lowering convenience for the owner.
Until the hackers figure out how to bypass the PIN code – and if the carrot is dangled, they will try.
Hackers are typically highly intelligent people who crave the challenge.
So, what else could we do?
The Lower-Tech Solution
As humans, how did we cope with unlocking our cars and starting them up before remote key fobs?
We coped, and we coped very well.
People walked up to their cars, and put the key in the door. They got inside and put the key in the ignition, and were on their way.
Why aren’t we still doing this?
Key systems without radio transmitters can still contain security codes, which could be read by the car when the key comes into physical contact with it.
All without broadcasting the security codes for hackers to scan and potentially use against you.
It would be harder to steal your car – and would our lives be that much more difficult if we stepped back to something like this?
Sometimes simple proven ideas are far better for us than fancy new ideas that haven’t been completely thought through.