[tor-bugs] #15998 [Tor]: suggestion: distributed captcha mechanism for hidden service DDOS defense

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#15998: suggestion:  distributed captcha mechanism for hidden service DDOS defense
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 Reporter:  hdqdak8v32aor  |          Owner:
     Type:  enhancement    |         Status:  new
 Priority:  normal         |      Milestone:
Component:  Tor            |        Version:
 Keywords:                 |  Actual Points:
Parent ID:                 |         Points:
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 Had an idea and couldn't find a previous
 instance via search.  If the idea is
 impractical or otherwise deficient feel
 free to close this ticket.

 Lately many hidden services have come under
 sustained DDOS attacks and have struggled
 to remain operable.

 A possible way to mitigate this problem
 might be to enhance Tor to support some
 sort of mechanism to push captcha processing
 out to either introduction points or
 rendezvous points so that DDOSers cannot
 overload hidden service systems.

 Numerous designs seem possible and I am
 not sufficiently steeped in the workings
 of Tor to venture a suggestion, but
 if the idea is of use I imagine there
 will be no shortage of approaches.

 However it does occur to me that it
 could perhaps be implemented in two stages,
 first a "quick-n-dirty" approach that
 is limited in scope and then a follow-
 on generalized approach that perhaps
 allows hidden services to push
 configurable captcha generation logic,
 perhaps in the form of LUA scripts
 or some similar mechanism.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15998>
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