# File lib/captcha/model.rb, line 30
      def captcha_must_match_known_captcha
        return true if self.captcha.nil? || self.known_captcha.nil?
        if self.captcha.strip.downcase != Captcha::Cipher.decrypt(self.known_captcha)
          if self.captcha_options[:base]
            self.errors.add_to_base(
              case self.captcha_options[:base]
              when true
                "Enter the correct text in the image (6 characters)"
              else
                self.captcha_options[:base]
              end
            )
          else
            self.errors.add(:captcha, 
              case self.captcha_options[:field]
              when true, nil
                "text does not match the text in the image."
              else
                self.captcha_options[:field]
              end
            )
          end
        end
      end