Workstation (Un)locking Using Bluetooth

When you use a workstation (PC, laptop or thin client), it’s important to lock it when you are away for a while or funny things may happen. Usually, the screen is automatically locked after a configurable inactivity period. To unlock it you need to type a password or, on some laptops, scan your finger print.

I tested a sympatic application for Microsoft environments called LockItNow!. It replace the standard locking mechanism used in the Microsoft OS by its own system. In the same time, other features are added:

  • It uses a different password than the one of the logged user (can be useful to give rights to unlock an open session without disclosing your own password to lock/unlock it.
  • A scheduled lock time can be configured (ex: a workstation in a public area during non-business time)
  • and… a (un)locking mechanism based on a Bluetooth pair!

The goal is simple: if the paired device is near the workstation, it’s kept unlocked and way you walk away with the device, it’s locked a few seconds later. You come back (with your coffie 😉 and it’s magically unlocked! Nothing to do.

Config with a phone
Config with a phone
Config without a phone
Config without a phone

There are two methods available to detect the presence of the phone: Bluetooth inquiry (a search) or Bluetooth connect (using a COM port mapped to the paired device). The first method is of course the best one but the application does not support all Bluetooth adapters (and my Dell laptop was not supported). As the iPhone does not provide a serial service via Bluetooth, I was unable to test mine. But it worked perfectly with a old Nokia phone.

Even if it’s funny to see your computer locked and unlocked automatically, this tool does not provide enough security. Your mobile can be stolen or your Bluetooth ID can be spoofed! A stronger authentication process is required. (Example: password + phone presence detected)

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