Create a Challenge and response functions that can be used accross a site built in Codeigniter

Create a Pop up that Generates 8 digit number. (This is the Challenge) Another page (Response generator). Only visible to certain user types Takes a Challenge number multiply by 'X' ( a number depending on "user type" of person creating Response)* id user who generated Challenge The Response can then be typed in the initial pop up along with the user that created the response. The check function takes ResponceGeneratedByUser, PermissionsTypesAllowed,ChallengeNumber, ResponseNumber. Run though the different permission types that are allowed and either accept or reject response