Hashing for fun and profit: Demystifying encryption for PCI DSS

or many people, cryptography is akin to biblical Gnosticism -- there are a few who intimately know cryptography and its s-boxes, permutations, salts, and other magic1 -- and then there are the rest of us whose eyes glaze over when the topic arises. This is partially because cryptography by design was once known only to the denizens of the National Security Agency and a few academics. Until 1996, it was illegal under federal law to export strong cryptography from the United States, which may have discouraged others from learning the art.