I have a simple contact form on this website that kept getting spammed. A
simple captcha at least gives them some work to do. In fact it has greatly
reduced the level of spam. I didn't want to use reCAPTCHA because it would make
my site dependent on an external service and, by extension, leak information
about my visitors.
Features and limitations
+ Very simple to integrate with any Python web framework. The library is
framework neutral. Example provided is for the awesome
"Pylons web framework."
+ Unlike some other solutions, this one does not require storage for
- Does not prevent replay. I will fix that if it becomes a problem. (Idea:
embed date in encrypted string... Expire 1 hour after... or make date part of
- Generates only a simple image which is trivially defeated with OCR. On
the plus side, that also means users will have no trouble with it either!