https://devzone.nordicsemi.com/f/nordic-q-a/76795/security-related-events-clarifyFrom SDK we can see that there is a lot of events about security. I&#39;ve read some of them by comments and still a little confused about the difference of them. Could anyone can explain a bit about them from the central side and peripheral side？ BLE_GAP_EVT_SEC_PARAMS_REQUESTen-USTelligent Community 13Mon, 28 Jun 2021 12:19:49 GMThttps://devzone.nordicsemi.com/thread/317476?ContentTypeID=1Mon, 28 Jun 2021 12:19:49 GMT137ad170-7792-4731-bb38-c0d22fbe4515:89564ec1-759b-4f19-b819-3d69913c8cc6Kenneth<p>There are message sequence charts that show what will trigger these events;<br /><a href="https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.2.0/group___b_l_e___g_a_p___m_s_c.html">https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.2.0/group___b_l_e___g_a_p___m_s_c.html</a></p> <p>Kenneth</p><div style="clear:both;"></div>