Can anybody remember the story, I think it was a few years ago, when a journalist warned in an article that messaging apps like Whatsapp are vulnerable because they rely on a server for key exchange, and all the security researchers requested that the story should be retracted because it would lead people to use SMS which is even less secure? I may be misremembering some details.
Warning that it's vulnerable because it relies on a server for key exchange is like warning that water is wet and you shouldn't let it loose in your house to prevent water damage. It's correct, but redundant. The very definition of end to end encryption is not trusting the server, so you need to verify the exchanged keys. This is a requirement in Signal, Wire, Threema, Jami, Briar, Element/Matrix, Keybase, OTR, and a…
Right. WhatsApp/iMessage etc end-to-end encryption is meaningless because a single firm can turn it off invisibly any time they like. In fact we only have their assurance that it even exists at all, given the difficulty of reverse engineering their protocols and checking everyone has the same clients.
I've felt very uncomfortable about the way Valley firms jumped on board the end-to-end bandwagon. The intentions are good and ones I wholeheartedly support, but the claims made for it are just not true. The WhatsApp paper is at least slightly less deceptive than it once was, and I guess that's progress of sorts, but the damage is done already. One day Facebook will discover some sort of burning reason why a WhatsApp user has to be decrypted, it will come out that this has been done, and trust will be irrevocably burned.