no circuit loops?
aas23 at hermes.cam.ac.uk
Fri Oct 24 09:46:34 UTC 2003
> On the one hand, a loop has an obvious threat from any "repeat node" since
> it can trivially recognize circuits with that loop and thus bypass it
> (long range padding and leaky pipes could reduce this slightly, but
> On the other hand, the absence of loops gives information about a
> circuit. E.g., there is an observer on OR_1's network connections.
> Alice connects through OR_1, OR_2, OR_3, OR_4, OR_5. OR_4 is bad.
> The adversary can now rule out OR_2 and OR_3 as exit points
> even though their net connections are not visible to it.
This is an interesting argument for having substantial numbers of Onion
Routers (but not *too many* as I argue elsewhere). I suspect if you have
many more routers than your route length, the problem becomes
Cambridge CB3 9ET
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