does the bonding feature encrypt data

[makouda]

I'm using the mouse example which use bonding and white list which allow to connect only to one central after performing the bonding

my question is, does the bonding feature encrypt data?? I mean if I bond my device and use sniffer, can I see clearly the frames data???

[run_ar]

Bonding features encryption, a 128 bit key is used for this. But it might still be possible to capture the frames. For bluetooth LE legacy pairing:
If the sniffer is present during the bonding procedure it will be able to capture the encryption keys and resolve the encrypted data. If the sniffer is turned on after the bonding procedure it will not be able to resolve the encrypted data. Using OOB could help avoid this.

For LE secure connections: The sniffer won't be able to capture the keys and resolve the encrypted data. However IO capabilities is necessary to avoid MITM attacks.