[tor-talk] Including Adblock to TBB to save bandwith

[Roger Dingledine]

On Mon, Dec 15, 2014 at 04:10:03PM +0100, intrigeri wrote:
> Hi,
> 
> Justaguy wrote (15 Dec 2014 13:44:05 GMT) :
> > What if torbrowser would include adblock, this would reduce the amount of bandwith
> > used, and thus increase the overal speeds @ tor
> 
> See "5. No filters" in
> https://www.torproject.org/projects/torbrowser/design/#philosophy

Yep. These are some good reasons to keep adblock et al out of Tor Browser.

Another good reason mentioned on this thread is limiting attack surface.

But that said, here are two good reasons to put it in:

A) Reduction of bandwidth, as the original poster here pointed out.
As a bonus, since some pages don't render until certain of the components
are there, by fetching fewer components we could see speed-ups that are
more than just about bandwidth.

B) Potentially significant anonymity gains against certain attacks. If
traffic confirmation attacks are trivial (I'm not saying we know they are,
but it's simplest to act as if they are), and websites with ads cause you
to reach out to many more destinations than you would otherwise, then each
of those new destinations presents a new risk that an adversary could see
traffic going over that path. Thus reducing the number of destinations --
especially common ones like the centralized ad servers -- could help a
lot against this attack.

For more context, see the "The paper also makes me think about exit
traffic patterns" paragraph in
https://blog.torproject.org/blog/improving-tors-anonymity-changing-guard-parameters
and the discussion around it.

--Roger