Add a .well-known option to allow homeserver admins to set the default E2EE behaviour back to disabled for DMs / private rooms (as it was before 1.6) for various environments where this is desired.
This variant would still allow users to enable encryption, so it would only influence the default behaviour.
In more detail, a homeserver admin can add the following to /.well-known/matrix/client:
{
"im.vector.riot.e2ee": {
"default": false
}
}
which will cause the following behaviour changes in Riot:
Encryption enabled tile for non-e2ee rooms

Please ensure we use a "positive" name for the option that is then disabled to avoid double negatives, so something like e2eeDefaultForPrivateRooms which defaults to true but can be set to false.
We also probably want the same option to control the verification toasts & dialogs after login / registration: there's no point verifying your devices if you're not using e2e (we may want to keep some form of the 'new login, was this you?' toast to help people notice unusual sign ins, but it would need different UX so I'd suggest this comes later).
We're continuing to discuss and revise the level of configurability to offer to here, so for the moment this is blocked on some product choices. Rest assured this remains a top priority for us; we just need to work out a few more details first.
@jryans a variation of https://github.com/vector-im/riot-web/issues/13678 might help here
I have updated the issue body to match our latest thinking around using .well-known to control and changes to feature behaviour. This should now be ready to implement.
@jryans a variation of #13678 might help here
Thanks for the .well-known reminder here. https://github.com/vector-im/riot-web/issues/13678 seems to be a more generic things we can experiment with separately, while for this case I think we'll accept a specialised config setting for now to move quickly. I think the ideal place for this particular kind of admin choice is likely something likely https://github.com/matrix-org/matrix-doc/pull/2301, if it someday comes to exist for real. For now, .well-known seems like the best option out of the things that already exist.
Updated issue body to warn in both room creation and account settings when disabled by admin.
Updated issue body to reflect that cross-signing toasts should still appear once you join an E2EE room.
Maybe better "default": "false" or "force": "false" instead of "enabled": "false"?
also I'm hoping the "false" is a typo and meant to be false (boolean, not a string).
Maybe better
"default": "false"or"force": "false"instead of"enabled": "false"?
They all seem equal parts okay and possibly unclear to someone. enabled seems to match the way we're thinking about the concept so that's why I went for that.
Maybe better
"default": "false"or"force": "false"instead of"enabled": "false"?They all seem equal parts okay and possibly unclear to someone.
enabledseems to match the way we're thinking about the concept so that's why I went for that.
If user see "enabled=false", he understand that it will be globally disabled, but users still can enable it, so this option is only disable it by default for DM, that's all.
To me enabled implies the other function of enforcing e2ee to be disabled, whilst "default": false gives the actual behaviour
Okay, I'm convinced, will update the spec. 😄 (Oh, I see @t3chguy already did!)
Show tile similar to the Encryption enabled tile for non-e2ee rooms
Where should we show this tile? The Encryption enabled tile is shown in place of the m.room.encryption event but in unencrypted rooms there is an absence of that event.
Do we additionally want to hide the Verify prompts on login? This seems to be handled by Dave's ongoing work

Show tile similar to the Encryption enabled tile for non-e2ee rooms
This has been descoped due to complexity with injecting tiles unrelated to timeline events and will be handled by next week's "Notifications" rework project.
Most helpful comment
We also probably want the same option to control the verification toasts & dialogs after login / registration: there's no point verifying your devices if you're not using e2e (we may want to keep some form of the 'new login, was this you?' toast to help people notice unusual sign ins, but it would need different UX so I'd suggest this comes later).