On 09/18/2017 09:27 PM, [email protected] wrote: > Thank you Micah and Michał, but I am not actually asking about a standard as > strong as 100% bulletproof anonymity or anything. I really am just concerned > about whether any of the methods on that list that I linked to would be > enough to leak cookie-like reference data between two separate Qubes security > domains.
Cookie-like reference data between two separate Qubes security domains cannot happen. This would mean one VM is able to influence the hard disk of another, which would be a vulnerability in Qubes. > Being tracked as I browse around *in* a given security domain is entirely my > problem of course, and I understand that. My only concern is working to > ensure that to an outside observer such as webservers and ad networks nothing > short of the shared IP address (and via Tor or VPN or different IPs honestly > allocated to different domains perhaps not even that) can act as a reliable > indicator that web browsing activity in one Qubes security domain is "linked" > to activity from another security domain via any secretly stored cookie-like > reference identifiers that get somehow leaked across domains. What can however happen is things like hardware fingerprinting through the browser, like CPU frequency measurements. Also, Qubes doesn't guarantee two VMs can't talk together, so if you have at the same time a browser in two VMs in two websites they may be able to talk together using such side channels (timing the cache, ultra-low-level stuff like that). So even though supercookies and the like aren't shared in Qubes, if you use an insufficiently anonymising web browser, a web site may be able to fingerprint your hardware through the browser (Qubes/Xen does nothing to prevent that for performance reasons), and then to link your hardware to different identities you used to browse different pages in different VMs. I don't know of any website that would try to talk to others through side-channels, but I seem to remember articles on hardware fingerprinting (esp. the cpu frequency and drift, iirc) through JS from a few years back, so I guess against state-of-the-art tracking systems Qubes will not be enough. -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/1720ec21-6433-8a0c-02bc-aeb17336fb8c%40gaspard.io. For more options, visit https://groups.google.com/d/optout.
