Bluetooth security supports authentication and encryption. These features are based on a secret link key that is shared by pair of devices. A pairing procedure is used when two devices communicate for the first time to generate this key.

There are three security modes to a device:

1. Non-secure: A device will not initiate any security procedure.

2. Service level enforced security: A device does not initiate security procedures. before channel establishment at the L2CAP level. This mode allows different and flexible access policies for applications, especially running applications with different security requirements in parallel.

3. Link level enforced security: A device initiates security procedures before the link set-up at the LMP is completed.