- Privacy in terms of BLE devices focuses on ensuring that untrusted parties are not able to track a device by its Bluetooth address
- Privacy is achieved by using a resolvable private address
Privacy Process for BLE §
- An IRK (Identity Resolving Key) is used in generating and resolving the Resolvable Random Private Address
- The IRK is generated by each device locally either randomly or assigned during manufacturing
- During bonding each device stores its peer’s IRK in what’s called a revolving list
- The IRK is used to resolve the private address of a peer device (when it receives the peer’s advertising packets at a later time) which is done by verifying that the hash included in the private address matches the output of the local has
Device Trust §
- A trusted device can bond with another. Binding is an optional step that takes place after pairing two devices
- The bonding process involves the storage of keys by each of the devices that are bonded with each other
- Bonding allows two devices to pair seamlessly in connection subsequent to the original connection when the two devices were paired
- One of the keys exchanged by the two bonded BLE devices is the IRK of each device involved