Correct parameter to sd_ble_gap_sec_params_reply() when bonding not allowed

Question

Hello, 
 I decided that bonding (does it equivalent to "pairing"?) is not allowed in my application, so I modified the following definition in main.c:
#define SEC_PARAM_BOND 0 //1 
 And inside the on_ble_evt() function, I am not sure which of the following 2 options is correct when replying to the BLE_GAP_EVT_SEC_PARAMS_REQUEST event, please advise. 
 option 1)
case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
err_code = sd_ble_gap_sec_params_reply(m_conn_handle,
BLE_GAP_SEC_STATUS_SUCCESS,
&m_sec_params);
break; 
 option 2)
case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
err_code = sd_ble_gap_sec_params_reply(m_conn_handle,
BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP,
&m_sec_params);
break; 
 Thank you!
Joseph

Pål Håland · Accepted Answer

Hi Joseph, 
 Bonding is just an extended version of pairing, where you exchange some keys that can identify the peer at a later point. (IRK or LTK). 
 In general if you don't want to use encryption at all, you should respond with option 2. 
 You can use option 1 if you have characteristics that require authentication. Then no device can start encrypting the connection, but they would have to initiate pairing first. 
 --
Pål