Firewall Wizards mailing list archives
Re: client puzzle protocol
From: Antonomasia <ant () notatla demon co uk>
Date: Thu, 17 Feb 2000 21:59:57 GMT
"Michael B. Rash" <mbr () math umd edu>:
scheme any different? The server still must maintain state for each connection request to know if any subseqent response solved the crypto puzzle correctly... hence we can DoS such a server in exactly the same way as the normal SYN flood; by maxing out this state table.
This might be avoided by something like "An option-based implementation of SYN cookies?" proposed here in December by Mikael Olsson <mikael.olsson () enternet se>.
In addition, even if there were a server-side limit on the number of connection requests made by a single client (which RSA does not seem to do) it would be easy to spoof packets from *many* different IP's in the same manner as the DDoS attacks and so this would be useless too.
It may prevent spoofing, but I think massive parallel puzzling by large numbers of zombies with genuine unwanted connections will beat this and anything else of the kind. -- ############################################################## # Antonomasia ant () notatla demon co uk # # See http://www.notatla.demon.co.uk/ # ##############################################################
Current thread:
- client puzzle protocol Michael B. Rash (Feb 15)
- Re: client puzzle protocol daN. (Feb 17)
- Re: client puzzle protocol Michael B. Rash (Feb 17)
- Re: client puzzle protocol Paul Cardon (Feb 20)
- Re: client puzzle protocol Michael B. Rash (Feb 19)
- Re: client puzzle protocol Ge' Weijers (Feb 21)
- Re: client puzzle protocol daN. (Feb 24)
- Re: client puzzle protocol Todd Joseph (Feb 20)
- Re: client puzzle protocol daN. (Feb 17)
- Re: client puzzle protocol Shafik Yaghmour (Feb 17)
- <Possible follow-ups>
- Re: client puzzle protocol Antonomasia (Feb 17)
- Re: client puzzle protocol Tommy Ward (Feb 19)
- Re: client puzzle protocol Gregory Stark (Feb 20)
- Re: client puzzle protocol Michael B. Rash (Feb 19)
- Re: client puzzle protocol Antonomasia (Feb 21)