No cross-room auth
@@ -299,6 +299,16 @@ space has a high rate of membership churn.
Things that were considered and dismissed:
+* Extend the auth rules to include state from other rooms. Although this feels
+ cleaner, a robust implementation would be a hugely complicated
+ undertaking. In particular, room state resolution is closely linked to event
+ authorisation, and is already highly complex and hard to reason about, and
+ yet is fundamental to the security of Matrix.
+
+ In short, we believe such a change would require significant research and
+ modelling. A solution based on such a foundation could not practically be
+ implemented in the near future.
+
* Rather than defining the mapping in the room, define a template power-levels
event in a parent space, which will be inherited by all child rooms. For example:
