Mac® Security Bible

7.13. Bluetooth Sharing

The final category of sharing in the Sharing pane of System Preferences is Bluetooth. Bluetooth is a wireless communication standard designed for relatively low-speed data transfer over short distances. It's often used for peripherals such as keyboards, mice, and headsets. All current Macs have Bluetooth transceivers, as do the vast majority of cell phones and many other electronic gadgets. Although Bluetooth doesn't have the bandwidth or range of Wi-Fi, because it's so common and so easy to set up, it's an ideal way to share files and data when other routes are unavailable.

Bluetooth security depends primarily on the concept of pairing. When you pair two devices, they confirm their identity to each other and thereafter can freely exchange information. Unpaired devices may be able to see each other but usually can't connect. For example, if you want to use a Bluetooth headset with your cell phone, you must perform a procedure that stores information about your phone in your headset and vice versa. If this procedure weren't required, someone else could use his or her headset to listen in on your conversations!

Pairing, in turn, requires that one device be able to detect the other and learn its name and unique identifier. When a Bluetooth device broadcasts its ID so that other devices can detect it, it's said to be discoverable. Typically, you make a device discoverable only for a short period of time (perhaps two or three minutes) — just long enough to pair ...