I'm currently taking one of Matt Blaze's courses at Penn (Operating Systems). It's cool to see one of my professor's papers posted on HN. If you liked this one, he also wrote another cool paper entitled "Cryptology and Physical Security: Rights Amplification in Master-Keyed Mechanical Locks." It discusses the ability to reverse-engineer master keys in the context of computer science. Here's a link:

http://www.crypto.com/papers/mk.pdf