Hi Stephane, I just found this older mail and didn't really see a reply, so here a quick note:
You are right that it's really hard to avoid tracking completely, just because if one flow stops sending to server but that the same time another flow starts sending with the same "speed" it likely that it is actually the same flow. Maybe a few notes on this are in the manageability document here: https://datatracker.ietf.org/doc/html/draft-ietf-quic-manageability-11#section-3.5 Not sure what else to say... Mirja On 07.06.21, 14:39, "QUIC on behalf of Stephane Bortzmeyer" <quic-boun...@ietf.org on behalf of bortzme...@nic.fr> wrote: I was thinking about the privacy risks of QUIC and there is one where I'm not sure what to think of it, and for which I cannot find any discussion in the archives of the WG. Long-term QUIC connections may enable some user tracking, even when the user changes its IP address, without even needing HTTP cookies or things like that. I am not sure it is a real problem in practice because it's not new (HTTP/2 offered similar possibilities), there are many other ways to track users (HTTP cookies, browser fingerprinting, Google Analytics), and they even work cross-servers. But it can be a problem for privacy-oriented technologies (QUIC cannot currently work over Tor but may be in the future?) I do not find discussions about that. Was it considered? (If so, you are welcome to reply "Search with mailarchive yourself" but I prefer if it comes with URLs and/or approximate datetimes.) Is it, for instance, a good idea to advise privacy-oriented clients to always shut down QUIC connections when IP address changes?
