The number one concern in today's technology is security. The more secure something is the better! So how does bluetooth ensure security?
Frequency hopping like crazy: Bluetooth uses something called AFH (Adaptive Frequency Hopping). It basically uses 79 channels in the 2.4 Ghz and it keeps hopping between them on a rate of 1600 hops/s, while observing the environment and excluding any existing frequencies from the hopping list. This greatly reduces interference and jamming attempts.
Undiscoverable: Unless you set your device to "discoverable" it won't respond to scanning attempts and your 48-bit BD_ADDR (the address that identifies your Bluetooth-enabled device) won't be revealed.
Pairing: Unless the devices are paired with the parties' consent they won't be able to communicate. A pairing request can only be made if you know the other device's BD_ADDR (through scan or previous knowledge).
What are some way people try to hack bluetooth?
Worms and viruses: A virus writer often builds malware specifically to attack mobile phones. The malware can spread via Bluetooth – as long as the device is set to “discoverable” – and is often hidden in the form of an app.
Bluesnarfing: Bluesnarfing exploits Bluetooth connections to steal information from the targeted device. A hacker wirelessly connects to your phone without your knowledge to access and download your phone’s contacts, calendar, pictures and other information.
Bluebugging: With bluebugging, a hacker completely takes control of your smartphone using a wireless connection. He will often disguise himself as the device you’re looking to connect to, like your headphones. Once connected, he can access your contacts, place calls as you, listen in on calls, read your messages and emails and even track your location all without you even knowing. It’s essentially as if they have a remote control for your phone.