Random image text generation?

[Leif K-Brooks]

Ben Finney wrote:
> Leif K-Brooks <eurleif at ecritters.biz> writes:
> 
>> Steven D'Aprano wrote:
>>> For a text only solution, consider putting up a natural language
>>> question 
>> That wouldn't work as a true CAPTCHA (Completely Automated *Public*
>> Turing test to tell Computers and Humans Apart), since making the
>> list of questions and answers public would defeat its purpose.
> 
> The "Public" part of a CAPTCHA is the algorithm. The data consumed and
> produced by the algorithm don't need to be publicly correlated -- and
> indeed shouldn't be, for exactly the reason you state.

When the CAPTCHA is based entirely on a fixed list of questions and 
answers, I think it's reasonable to treat that list as part of the 
algorithm, since the CAPTCHA couldn't function without it. Similarly, I 
think most people would consider an image-based CAPTCHA for which the 
algorithm but not the fonts were available to be non-public