Kind of encryption is used for Bluetooth security

What kind of encryption is used for Bluetooth security? Explain

The encryption standard 8-128 bits length is used for encryption in Bluetooth security. This standard prevents receiving the transmission from other devices. The security mode 2 enables the Bluetooth device initiates security procedures after the channel is established. The security mode 3 enables the Bluetooth device initiation security before the channel is established, at the lower layers.