I have an airshow website where volunteers and vendors can apply online (www.hollisterairshow.com) . The city attorney requires that we have a wet signature on a printed application form so the volunteer/ vendor currently has to print their application at the time they apply online, then sign it and mail it in and this works fine. Unfortunately, we have had a lot of instances where volunteers/ vendors needed to print their application again and the only way we could do this was for an administrator to print their application to a pdf file and e-mail the file to them. So, I'd like to improve this process by automatically sending an e-mail to the applicant when they apply online with a link to a printable page and containing a key pointing to their application. This way, volunteers/ vendors could print and sign their application whenever they want and as many times as they need to. Each volunteer is a single row in a volunteer table and each vendor is a single row in a vendor table.
The key I use in the tables is a sequential key automatically incremented by MySQL so I would end up sending them a link looking something like www.hollisterairshow.com/printvolunteerapp.php?volunteernumber=27 . This would work, but it wouldn't be hard for a volunteer to change it to a different volunteernumber and so get access to someone else's personal information, which would not be acceptable. So, I'm thinking I need a secondary key that is somehow scrambled and used as an secondary index in the table so I'd be sending a link that mght look like www.hollisterairshow.com/printvolunteerapp.php?volunteerkey=sygew . So I'd really appreciate some advice on how to create a scrambled secondary index for each volunteer or vendor and plug it into the link I send them in the e-mail.
Thanks for any advice.