BLE Encryption without any

Question

I'm using the nRF52DK and S132. Is it possible to encrypt a link without any pairing, bonding and authentication process ? Please show me the way how to implement with the APIs if it is.
Thank you.

Petter Myhre · Accepted Answer

The peripheral/slave cannot initiate the encryption procedure, it cannot call sd_ble_gap_encrypt(). 
 It can only call sd_ble_gap_authenticate() , and then it is up to the central device to initiate the procedure and encrypt the link (if the devices have a bond).