8.2. Aligning Interest with Capability

Originally published in Wired, 1 June 2006

Have you ever been to a retail store and seen this sign on the register: "Your purchase free if you don't get a receipt"? You almost certainly didn't see it in an expensive or high-end store. You saw it in a convenience store, or a fast-food restaurant, or maybe a liquor store. That sign is a security device, and a clever one at that. And it illustrates a very important rule about security: It works best when you align interests with capability.