title: ColdFusion Cookie/Form Submission Loophole
body: <p>Okay so here is my problem. I have developed a framework which does the following: </p>
  
  <p>If, for example, you have four webpages... but you only want to allow users to reach the "4th" webpage after progressing through pages 1-3 sequentially - I have built this functionality (basically I set an encrypted cookie keeping track of what the user has completed thus allowing to know what they should be able to access). There are two parts of it:</p>
  
  <p>1) If a page does NOT have a quiz, the user must only visit the webpages sequentially to be allowed to view the 4th page in the "progression".</p>
  
  <p>2) However, if a page has a quiz on it, the user must successfully pass the quiz to go on to the next sequential page.</p>
  
  <p>Now... Here is the real biggie... The last page will often be a web form which, obviously, I only want an individual to fill out and submit if they have reached the form by sequentially getting to that last page in the progression... BUT I found a flaw in the system. If someone were to go completely through the progression and fill the form out... they could delete their browser's "form data" and go "back" to the form and allow a friend to fill the form out. That would be detrimental to the system, and the users who will be navigating this progression are GOING to look for ways to get around going through it.</p>
  
  <p>Some of the suggestions I will probably get will not be possible given the larger framework I am in, but rather than list all of the impossibilities I would like to see what you guys thought would be a way of getting around this issue?</p>
  
  <p>P.S. This functionality is built in HTML and ColdFusion.</p>
  
  <p>Thank you for any feedback, it is a great help!</p>
  
  <p>EDIT: 
  Keep in mind the user must be able to back track any previous page they already completed.</p>