This is addressed in https://signal.org/blog/private-contact-discovery/ – using Intel SGX, it's possible for the clients to verify that the server is running the code it should be running. I'm not sure whether this is already deployed, but it refutes any claim that Signal isn't serious about your concern.
I don't see how federation is related to this at all. We know you're bummed about it, you don't need to inject it into every subthread.
SGX alone cannot solve this problem. Even in the idealized case, you can sniff traffic on the router to find out which user IPs are talking to each other and when.
Did you read that work? I did: I was on the review board that made the decision to accept it for Black Hat. Could you map Yogesh's research to something Signal is actually proposing to do and explain in any detail what the actual threat you're talking about is? Thanks.
>I did: I was on the review board that made the decision to accept it for Black Hat.
Probably makes you more qualified to talk about SGX than me, so yes, I concede that the paper may not be relevant because your understanding of it is probably better than mine.
With that, I asked you a more fundamental question, given that you are knowledgeable about this and may be able to provide an answer.
What I'm asking is whether you had a coherent argument about weaknesses in SGX based on Yogesh's research that would keep it from functioning in Signal's contact discovery scheme, or whether you saw the letters "SGX" in a thread and posted the first link you could find about issues with SGX. Maybe you should find a better link? They're out there.
I don't see how federation is related to this at all. We know you're bummed about it, you don't need to inject it into every subthread.