Car manufactures like BMW, Audi or Mercedes-Benz all provide mobile applications to control your car. All apps share really critical functions like remote lock/unlock or the ability to find your car based on current GPS location.

Can somebody provide any additional information how this kind of communication is secured?

On the BWM app you just have to enter your login information of the BMW connectedDrive Portal and you're set up and have full control over your car. I really doubt the security of real world cars protected with user chosen passwords.

My best guess is that some public key infrastructure is used but I can't find any information.

  • A theory, with absolutely no research/evidence to back it up: your phone connects uses stored login credentials to authenticate to a server set up by the car manufacturer. The server then authenticates to the car with a certificate system and tells it to perform the function. No part of this system, to my knowledge, is insecure, specifically if the car shares a key with the account that is known to your phone, but not the servers. Then even if the servers were hacked, they could use an onion routing scheme to ensure the hacker was unable to access any vehicles.
    – KnightOfNi
    Commented May 23, 2014 at 23:32

2 Answers 2


For Tesla, the car and the app communicate with the Tesla servers over HTTPS. The app logs in here https://portal.vn.teslamotors.com/ and there is some third party API that can interact with the car on Google's Appspot (teslaglass.appspot.com) for Google Glass integration.

Some weaknesses in the authentication and APIs have been discovered and published. Localization and remote unlocking was possible.

  • Thank you very much I didn't look into Tesla yet. This gives some great insight! Unfortunately there's no information about the cryptography used besides the openVPN protocol.
    – Youleean
    Commented May 24, 2014 at 13:23

The current version of a premium German car manufacturer works by registering in the website in order to get credentials (user and password) downloading an app, authenticating against the server and finally connecting the device to your car either via USB or Bluetooth source

However, there were flaws in its first release. Take a look:

A security vulnerability in BMW’s Connected Drive system allowed researchers to imitate BMW servers and send remote unlocking instructions to vehicles...

“They were able to reverse engineer some of the software that we use for our telematics,” said Dave Buchko , a BMW spokesman. “With that they were able to mimic the BMW server.”...

The auto maker has already started sending out software patches to the 2.2 million cars equipped with Connected Drive...

The fix adds HTTPS encryption to the connection from BMW to the car, which runs over the public cellular network...


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