[jiiam]

I am saying that in practice the security might be structured in such a way that it requires several different parties to connive, rendering it essentially fine.

I mean, having to modify server code in order to access data that is "effectively plaintext" is not so different from installing a backdoor inside the client: it's not like the user has any choice of client, so even for apps like whatsapp and signal that run E2EE one is still making a leap of faith.

If we add the fact that everything runs inside an os built by companies who may or may not be constantly spying on their users we could say that by definition there's a lot of stuff in our lives that lives in "effective plaintext".

[jiiam]

EDIT: regarding the part about signal and whatsapp I must clarify that of course the possibility of inserting a backdoor on the server side is far more dangerous than the client side: Signal has verified builds so a backdoor would be evident and the user could stop using the service. And the same actually holds true for any app using E2EE if the user simply avoids autoupdating and wait for some confirmation that it is ok to update, at least as long as we can assume that any client side backdoor would be found by independent researchers.

I also want to repeat the original point that started this whole conversation: the point was how easy it would be for Telegram to access the chats and if the justice system can compel them to do so.

When people say it has the data in plaintext, I take as a "they can access them whenever the want right now without changes", and yes of course the could ultimately access the data (in fact they don't claim to be unable to). What they claim (and I believe it feasible) is that even if a judge seized all the assets and servers under his/her jurisdiction it would be impossible to decrypt any user data.