6. Bluetooth Security

6.1 Representation of Bluetooth Parameters

• Bluetooth device address (BD_ADDR) is the unique 48 bit (baseband level) address of a Bluetooth device. At the User Interface level the address is represented as 12 hexadecimal characters, possibly divided into subparts separated by ':', (e.g., 000C3E3A4B69 or 00:0C:3E:3A:4B:69) with MSB -> LSB 'natural' ordering (Big Endian format).
• Bluetooth device name is a user-friendly name of the device which may be up to 248 bytes in length, although a generic device is not expected to handle names more than 40 characters long. Often devices with limited display capabilities may use only 20 characters.
• Bluetooth passkey (PIN) is the key used to authenticate two Bluetooth devices (that have not previously exchanged link keys). The Bluetooth PIN has different representations at different levels. PIN_BB is a 128 bit (16 bytes) key used in baseband level during pairing procedure while PIN_UI is the character representation of PIN_BB (coded using Unicode UTF-8) used at User Interface level.
• Bluetooth Device Class is a (bit field) parameter used to identify the type of device and the services supported.