Dynamic Paypal button encryption

Question

I\'m designing a Order Site using PHP & Mysql. In the final stage the user is given Paypal buttons to pay for the Orders he has made. So, the Item Name, Value are variab

Answer 1

Couldn't anyone with your paypal email adress send you a bogus invoice, asking for product names at the wrong prices? If they are going to go through the trouble of changing your js/html code to send you a bogus invoice... they could just write their own (just a form submit to 'paypal.com/cgi-bin/webscr'). All you really need is the seller's paypal email right?

So why all the trouble of encrypting buttons?