Rapid Access Protection is a PHP security system that will disallow end user from rapidly accessing / reloading your webpage in an attempt to abuse it or bring your website down.

Small class for preventing that data is sent more than one time by a user if he presses Reload on his browser by setting a token that is written to the session and also placed as a hidden filed in a form. If those two values aren't the same, you get a boolean false by the isValid() function.