A different approache for the captcha.. instead of using a blurred image use some text and than ask a question about the text like
What does the 2nd word in the first line of the 4thparagraph say? Things to make sure: - Use enough texts so that guessing the correct word is not possible. - Use random word extraction to make the word different on each invocation. - Use different questions types and mix numbers and words. Like what is the word after the first word... stuff like that 10 different question should suffice - make sure that you have a timeout or relocation after a wrong word to make brute force attacks unattractive or even impossible This should be fairly easy to implement using db and php and is not quite as complicated as creating a blurry image. (IMHO) The system is easy to extend and easy to use by humans. Regards Stefan Langer
