https://devzone.nordicsemi.com/f/nordic-q-a/14573/secure-connections-only-modeHow do I enable Secure Connections Only mode on S130/nRF51? Alternatively, how do I tell if pairing was performed using LE Secure Connections?en-USTelligent Community 13Mon, 20 Jun 2016 11:55:10 GMThttps://devzone.nordicsemi.com/thread/55645?ContentTypeID=1Mon, 20 Jun 2016 11:55:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6025f729-0795-4328-a1c8-3a3cdcab6d84Hung Bui<p>Hi Tim,</p> <p>You can find the pairing parameters from the peer device when BLE_GAP_EVT_SEC_PARAMS_REQUEST event occurs. If you don&#39;t want to bond with a device doesn&#39;t support LE secure connection you can reject that with the sd_ble_gap_sec_params_reply().</p> <p>In addition, when you declare a characteristic, you can choose the security level. If you choose security level 4, BLE_GAP_CONN_SEC_MODE_SET_LESC_ENC_WITH_MITM() , bonding with LE Secure connection will be required if the peer wants to read data from the characteristic.</p> <p>When 2 device paired, you will receive BLE_GAP_EVT_AUTH_STATUS, and you can find in the parameter comes (ble_gap_evt_auth_status_t) with the event the security level that the connection currently is.</p><div style="clear:both;"></div>