• Referred to as a Bluetooth MAC address is a 48-bit value that uniquely identifies a Bluetooth device
  • There are two main types of Bluetooth addresses: public and random

Public Address

  • A global fixed address must be registered with the IEEE
  • Follows the same guidelines as MAC address and will have a 48-bit extended unique identifier

Random Address

  • More popular than public ones since they do not require registration
  • It can be programmed into the device or generated at runtime
  • There are two types: static and private

Random Static Address

  • An alternative to the public address can be assigned and fixed for the lifetime of the device or it can be changed at boot
  • It cannot be changed during runtime

Random Private Address

  • There are two types: resolvable and non-resolvable
  • Used to protect the privacy of a Bluetooth device by hiding its identity and preventing tracking

Resolvable Random Private Address

  • Designed to prevent malicious third parties from tracking the device while still allowing one or more trusted parties to identify the device of interest
  • It is resolvable using a key shared with a trusted device — this is the IRK
  • Generated using an IRK and a random number
  • This address changes periodically (recommended to change it every 15 minutes)

Non-Resolvable Random Private Address

  • This type changes periodically
  • Unlike resolvable address, it is not resolvable by any other device and its sole purpose is to prevent tracking by any other BLE
  • It’s not very common but is sometimes used in beacon applications