This might be a general question about any anonymizing service, but I'm new here and curious about, but not super familiar with, Tor.
Suppose there's a service that engages in some handshake with clients that takes the form of a 'call-and-response'. (The client has to make some decision in response to content at an application level. )
They also have some data stored with the service, so they need to authenticate. So later sessions can be compared against this one.
It seems like the service should get a full round trip time for packets, all the way back to the source, along with a reasonable location for the exit node (they can traceroute to that point).
Latency can be impacted by so many other factors, (including tor routing) so it's definitely noisy data, but the more a person visits, each time from a different tor node, can't the service do a clustering analysis to get a gradually improving picture of the person's physical location?
Is there something that prevents this gradual acquisition of data?