In some environments, governments and regulated organisations can't simply put people in a room and let them talk. What can be shared, and who can read it, is governed by a formal classification policy and by the clearances held by everyone present.
This talk walks through a working implementation of security labelling in Matrix using Synapse, Element Web and Advanced Identity & Access Management. We'll cover how policies are expressed, how labels attach to rooms and messages, and how the server enforces them. We'll then finish with a live demo.