This whole business has got me wondering if it's even theoretically possible to prevent the site identity being visible to middlemen. Like you said below, even

This whole business has got me wondering if it's even theoretically possible to prevent the site identity being visible to middlemen. Like you said below, even without SNI the cert is sent in the clear, and I can't think of a way around that. You'd need to somehow set up a secure channel before communicating site identity, but encryption without authentication is insecure in the face of MITM, and you need to establish site identity before you can authenticate the server. I suppose, with IPv6, we could do away with shared-IP virtual hosting, and hence SNI at least; and perhaps we could even devise a system whereby the domain is omitted from the cleartext-transmitted handshake, say by using the IPv6 address as the cert's DN instead... but then that numeric address would serve as a surveillable site identifier, and you can still be tracked. Is there any active research in this area? Is it provably impossible? Anyone know?