>When TLS is used there is no metadata either... server x talked to server y for a while, but what, if anything, happened we know not. Quite a bit of metadata

>When TLS is used there is no metadata either... server x talked to server y for a while, but what, if anything, happened we know not. Quite a bit of metadata really... Client X: IP address Server Y: IP address Client X request: TLS parameters that can be analyzed through TLS fingerprinting Server Y response: Hostnames supported by SNI Server Y response: TLS parameters that can be analyzed thorough TLS fingerprinting