[tor-talk] Fwd: Anonymous to attacks Hidden Wiki and othershiddenservice

[Eugen Leitl]

On Mon, Oct 24, 2011 at 01:46:13PM +0200, Jeroen Massar wrote:
> On 2011-10-24 13:34 , hikki at Safe-mail.net wrote:
> [..]
> > The problem is that they're using denial of service attacks to overload the 
> > servers, and parts of the Tor network as a result. Tor doesn't seem to 
> > handle this very well.
> 
> The internet does not handle (D)DoS attacks either.

Don't know what the internet is, but if you speak BGP on the Internet
you can always nullroute the target, or the origin network.
 
> > This takes down hidden services and nodes, 
> > consequently censors Tor hidden services and makes several circuits halt. If 
> > that isn't an attack on Tor, then I'm a fish with wings.
> 
> Wow, you are a fish with wings and you can even write emails ;)
> 
> 
> DoS attacks by overloading a network are always possible and the only
> real solution to that is to add way more capacity than the adversary has.

That's the brute force way to do it. Smarter ways would be use
connectionless protocols, or use proof of work (like hashcash)
in order that using the network at high priority needs credits
which have to be earned by being a member in good standing (as
seen from other nodes).
 
> As with Tor there is no way to identify the source node, implementing a
> rate limit on source is impossible. Doing rate limiting on the
> intermediate nodes would just cause a network-wide ratelimit and also
> impeed other traffic.
> 
> And if it was a proper DDoS attack you would run out of filtering
> resources before you ran out of capacity.
> 
> In other words: not much you can do about it but add more nodes with
> more capacity.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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