Which is a fairly ambiguous question and could be interpreted several ways so I went mainly for the E2E case (as it's the new thing).

Could also be interpreted as how can we show only paid users can access it? Or that certain features will be disabled with E2E?

What I replied with covers both E2E and the current state equally tbh (the linked article did it before with ECB). There are always limitations to what is possible.

I could break into the Zoom servers to make sure everything is kosher. But that's illegal.

If WhatsApp started transmitting E2E keys back to their servers people would find that out client side through network packet inspection, not server side.

Security researchers are limited in the tools/methods they can use. We have to work with what we've got at our disposal.

> Security researchers are limited in the tools/methods they can use. We have to work with what we've got at our disposal.

Which is exactly why "trust us, we're not going to do anything with these keys" is a ridiculous state of affairs and shouldn't be tolerated. We can't show that they're actually doing what they say, and it'll be years after they implement mass surveillance on the behest of law enforcement before someone leaks something.

Perfect security doesn't exist. If humans are involved at any point, it's not perfectly secure. The One time pad is a great testament to that.

Should we work towards an ideal? Sure. Should we stress out that things aren't perfect? Probably not.

It's an iteresting technical idea though. Would be interesting to see if any existing systems have a "canary" element to them.

There's a very simple solution to "the provider cannot prove that it will not misuse its access to the stream" - it's to use e2e encryption.