diff --git a/code/modules/security_levels/keycard_authentication.dm b/code/modules/security_levels/keycard_authentication.dm
index fffc79fdbbe..62b0089d472 100644
--- a/code/modules/security_levels/keycard_authentication.dm
+++ b/code/modules/security_levels/keycard_authentication.dm
@@ -22,6 +22,8 @@ GLOBAL_DATUM_INIT(keycard_events, /datum/events, new)
 	var/datum/callback/ev
 	var/event = ""
 	var/obj/machinery/keycard_auth/event_source
+	///Triggering ID card relayed to auth devices to make sure two keycards are used.
+	var/obj/item/card/id/triggering_card
 	var/mob/triggerer = null
 	var/waiting = 0
 
@@ -65,27 +67,35 @@ GLOBAL_DATUM_INIT(keycard_events, /datum/events, new)
 /obj/machinery/keycard_auth/ui_act(action, params)
 	if(..() || waiting || !allowed(usr))
 		return
+	var/obj/item/card/swipe_id = usr.get_idcard()
+	if(!swipe_id || !istype(swipe_id))
+		to_chat(usr, "<span class='warning'>No ID card detected.</span>")
+		return
 	switch(action)
 		if("red_alert")
 			if(!event_source)
-				sendEvent(KEYCARD_RED_ALERT)
+				sendEvent(KEYCARD_RED_ALERT, swipe_id)
 				. = TRUE
 		if("emergency_maint")
 			if(!event_source)
-				sendEvent(KEYCARD_EMERGENCY_MAINTENANCE_ACCESS)
+				sendEvent(KEYCARD_EMERGENCY_MAINTENANCE_ACCESS, swipe_id)
 				. = TRUE
 		if("auth_swipe")
 			if(event_source)
+				if(swipe_id == event_source.triggering_card)
+					to_chat(usr, "<span class='warning'>Invalid ID. Confirmation ID must not equal trigger ID.</span>")
+					return
 				event_source.trigger_event(usr)
 				event_source = null
 				. = TRUE
 		if("bsa_unlock")
 			if(!event_source)
-				sendEvent(KEYCARD_BSA_UNLOCK)
+				sendEvent(KEYCARD_BSA_UNLOCK, swipe_id)
 				. = TRUE
 
-/obj/machinery/keycard_auth/proc/sendEvent(event_type)
+/obj/machinery/keycard_auth/proc/sendEvent(event_type, obj/item/card/id/swipe_id)
 	triggerer = usr
+	triggering_card = swipe_id //Shouldn't need qdel registering due to very short time before this var resets.
 	event = event_type
 	waiting = 1
 	GLOB.keycard_events.fireEvent("triggerEvent", src)
@@ -93,6 +103,7 @@ GLOBAL_DATUM_INIT(keycard_events, /datum/events, new)
 
 /obj/machinery/keycard_auth/proc/eventSent()
 	triggerer = null
+	triggering_card = null
 	event = ""
 	waiting = 0