Last week, I visited the 22nd Chaos Communication Congress in Berlin. One of the presentations was about Bluetooth hacking. My Dell Latitude D800 laptop was suspended and stowed away in my backpack, but during one of the live demonstrations, its corporate Intranet name appeared on the presentation screens. As indicated by the blue light, Bluetooth is still active on the D800 even in suspended mode. And I didn't bother to change the default configuration.

While the laptop didn't get hacked, I prefer to not broadcast the company and office I work for while walking around. If you use the bluez-utils RPM, this can be prevented by changing the default /etc/bluetooth/hcid.conf as follows:

# Default settings for HCI devices
device {
    ...
    # Local device name
    name "foobar";
    ...
    # Inquiry and Page scan
    iscan disable; pscan enable;
    ...
}

The default name is "%h-%d", which is the host name and device ID. Depending on your network configuration, this can reveal quite a lot about where you come from. Also, inquiry scans are enabled by default, so anyone can detect the name of your Bluetooth device.

After you have changed the configuration options, run service bluetooth restart to active them.