Henning Thielemann <lemm...@henning-thielemann.de> wrote: > > On Fri, 13 Mar 2009, Benjamin L.Russell wrote: > > > Why not ask new users to identify letters in a random bitmapped > > image of a string, as is commonly done? > > I assume, because those images are > 1) not accessible by blind people > 2) can be decoded by spammers, since they know how the images are > generated by common software. > Thus my suggestion was a simple Haskell specific question, which > cannot be answered by stupid spambots. > http://recaptcha.net is believed to be spam-proof, and there's good reasons to believe so, see http://recaptcha.net/security.html : It starts off with text that can't be OCR'd, in the first place. It also features an audio mode for accessibility.
Question-based captchas provide security by rarity. You can be sure that if a spammer really, really wants to spam on the wiki, it won't take long before a program is written that memoises all questions and answers. -- (c) this sig last receiving data processing entity. Inspect headers for copyright history. All rights reserved. Copying, hiring, renting, performance and/or quoting of this signature prohibited. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe