BLE - oob

[Roei]

Hi,

When using LE secure - what exactly is exchanged via OOB channel? Is it all the procedure until LTK generation?

Thanks!

[Hung Bui]

Hi Roei, 
Please have a look at section 2.3.5.6.4 in Bluetooth Spec Vol 3 Part H v5.2 

So the information exchanged is A, ra, Ca and B, rb, Cb on the other side. 
These are the information to avoid MITM. After this confirmation at step 5a/b the LTK will be generated on each side.