Eavesdropping security

At times very sensitive data is transmitted using the Bluetooth radio link. The standard has therefore incorporated several mechanisms against unauthorised eavesdropping and undesired manipulation.
The data is secured with a 128 bit long encryption and therefore can only be opened by the correct receiver. A new encryption is generated for every connection. The devices recognise each other by a type of "secret password". The manufacturers of the devices have the possibility to protect especially sensitive data with other types of security mechanisms.