RE: NRF51822 Authenticate and Encrypt functions

tnesheim — Mon, 29 Jun 2015 02:33:41 GMT

Thanks for your help, this cleared things up for me.

RE: NRF51822 Authenticate and Encrypt functions

Pål Håland — Fri, 26 Jun 2015 05:28:52 GMT

Hi,

you are right that the link will always be encrypted when using the bluetooth way of authenticating.

While doing authentication the link is actually encrypted in the process with the link settings that you decided. Thus another encryption is not necessary. If you at a later point disconnect, or would like to do a key refresh of the link. Then you can use the sd_ble_gap_encrypt(..) with the keys that you received in the BLE_GAP_EVT_AUTH_STATUS.

The only way of authenticating without encryption is to distribute IRK or CSRK to identify that the peer device is actually a device that you have authenticated with previously. CSRK is something that we don't support.

What you could do, is to implement some sort of proprietary authentication if you control the app on both sides of the link.