If you have trouble getting simple_captcha to work with your Rails application, i.e. you enter the correct captcha string but still get the
“Secret Code did not match with the Image”
or similar error, look for this error in your log:
Can’t mass-assign these protected attributes: captcha_key, captcha.
To solve this issue, you’ll have to add
attr_accessible :captcha, :captcha_key
to your model. Here’s how to test simple_captcha.