Would this not be too easy a pick to bypass? With the use of Aspell or any spellchecker, I could quite reliably find the typo automatically. If you added a word that would be a good English word but clearly didn't fit in the sentence, that would be another matter, but that would be also very hard to do randomly with certainty that it will be clear what the inserted word is.
in reply to Re: howto: Perl CGI, image with random scewed text for account creations
in thread howto: Perl CGI, image with random scewed text for account creations