In a recent posting, I explained how a vast space of cryptographic keys can be represented by a small piece of data. That’s due to the sheer power of exponential growth. To see a vast space of keys arising from sheer ingenuity, it’s worth a visit to the Musée Cluny in Paris, which houses a number of medieval examples.

This wild menagerie makes our blunt-toothed modern housekeys look rather tame. And indeed, Matt Blaze, a colleague in computer security, has shown that locks and keys today are badly under-engineered.