[tor-talk] Defense against DDoS Attacks in Tor

coderman coderman at gmail.com
Fri Nov 14 20:55:52 UTC 2014

On 11/13/14, IGNACIO GAGO PADRENY <igago at ucm.es> wrote:
> ...
> I am currently studying network security and I am focusing on defense
> against DDoS attacks in Tor. I have read a few papers (replay attack,
> sniper attack, etc.) but most of them are not recent.

i assume you looked over http://freehaven.net/anonbib as well.

> My aim is to develop
> (theoretically or in practice) a defense but I would really appreciate if
> you could tell me current attacks which have no defense or are the most
> successful ones.

DoS are all "successful", by some measure.

ordered by hardness, consider:

 0. application level, like slowloris or computational DoS. [ see
torhs-pyloris-nov9.tgz on #8902 ]

 1. hidden services in general, roles like HSDir or Rendz., high
connection rates, stream isolation impacts. [ see list at
for enumeration of many known attacks ]

2. protocol issues, circuit extension attacks, shared gateways
manipulation, predecessor attacks, etc.

3. high capacity relay performance issues, tuning, clogging, etc.

messing with the fast relays most difficult. from there, considerably
easier to deny service. a hard problem.  good luck! :)

( most don't even try to fix 0 or 1 at all... )

best regards,

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