I've proposed a solution to adding authentication to MQTT-SN in the
style of MQTT 5.0 to the issue https://issues.oasis-open.org/browse/MQTT-568
I've also posted a longer discussion on my blog:
I will arrange a committee meeting soon to discuss this and some other
proposals I have (I have been waiting for the availability of some
participants) but in the meantime I would like to receive comments.