[tor-dev] Improving Private Browsing Mode/Tor Browser

Robert Ransom rransom.8774 at gmail.com
Wed Jun 22 21:33:48 UTC 2011

On Wed, 22 Jun 2011 22:30:40 +0200
Georg Koppen <g.koppen at jondos.de> wrote:

> Sticking to the blog post (one of) its central idea seems to be to
> isolate the identifiers and state to the top-level domain in the URL bar
> as "activity in Tor Browser on one site should not trivially
> de-anonymize their activity [i.e. the activity of Tor users, G.K.] on
> another site to ad networks and exits". I am wondering whether this idea
> really helps here at least regarding exit mixes. If one user requests
> google.com, mail.google.com and other Google services within the 10
> minutes interval (I am simplifying here a bit) without deploying TLS the
> exit is still able to connect the whole activity and "sees" which
> services that particular user is requesting/using. Even worse, if the
> browser session is quite long there is a chance of recognizing that user
> again if she happens to have the same exit mix more than once. Thus, I
> do not see how that helps avoiding linkability for users that need/want
> strong anonymity while surfing the web. Would be good to get that
> explained in some detail. Or maybe I am missing a point here.

If you maintain two long sessions within the same Tor Browser Bundle
instance, you're screwed -- not because the exit nodes might be
watching you, but because the web sites' logs can be correlated, and
the *sequence* of exit nodes that your Tor client chose is very likely
to be unique.

Robert Ransom

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