Why is “owned by the users” (whatever that means) the quality you’re testing cryptographic protocols against?
replySignal's has buildable source code on the client side and all. However, the server code is closed source and the developers have made disquieting changes like uploading most users' contact lists to the server protected only by Intel SGX that is known to have vulnerabilities exploitable by a nation-scale actor.
replyThe point of E2EE is that you don't need to trust the server that you're talking through. A secure E2EE scheme is secure in the presence of an actively malicious server.
replyI think SGX is a red herring in this context. You can find it risky or not, but it's (1) not material to Signal's E2EE property, and (2) materially better than email, which sends all contact metadata in plaintext, regardless of whether you try and encrypt your message bodies. Bringing it up in this context seems like a category error.
XMPP + omemo
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