Requiring clients to solve computational puzzles...

Posted by acidzombie24 on Stack Overflow See other posts from Stack Overflow or by acidzombie24
Published on 2010-05-06T20:51:04Z Indexed on 2010/05/06 21:18 UTC
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puzzle

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brute-force

Not that I need it, but it was interesting to hear someone speak about their server and protecting it from DOS attack by having a puzzle that the client must solve before the server will do anything (it doesnt do allocations or make a session unless solved).

The person also said puzzles can be made to take a quick amount of time or long. And they are easy to check for correct solutions but difficult to solve.

What are these puzzles? I never heard of one. Can someone give an example (or a link)?

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