BLE - MITM protection

[Roei]

Hi,

I understand that we have several types of sec_modes.

However, regarding modes with MITM - I don't understand how exactly those modes protect from MITM. What does it do?

Thanks!

[Kenneth]

MITM require the user to actively input a passkey that is displayed on the peer device. Thereby it is not possible for a man in the middle (MITM) attack. You can refer to the bluetooth core spec for more information about the various security modes and levels.

Kenneth

[Roei]

Hi,

What about BLE connection with a PC, via NFC?

What is the meaning of MITM configuration in this case?

Thanks!

[Roei]

Any ideas?

[Kenneth]

It's out of band exchange of key, in this case over NFC. This have very short range, so any attacker would need to be very close.

Kenneth

[Roei]

Do you mean diffie hellman key exchange?

[Kenneth]

Please read litterature you may find on Bluetooth core specification. Your questions are all good, but I can't explain the details  to your, you need to read up on the Bluetooth core specification.

Kenneth