Why do you lock your door?

2 factor authentication, key space, security by obscurity, public and private keys; all of these things, and many other conventions of digital security, had their origin well before the birth of the computer. Today most security professionals think of locks as curiosities or puzzles, and are well acquainted with the idea that "locks keep honest people honest." However, physical security has a rich history and our modern relationship to locks is very different than it was even a hundred years ago. In this talk we'll explore the history of physical security, from the origins of the lock, to the locksmith King of Worms, to the great lock controversy of 1851 and beyond. Knowing how different times and cultures designed, attacked and lived with locks provides remarkable context to the modern history of digital security.