Why has public-key encryption been so important?
Cryptography is the most flexible way we know of protecting communications in channels that we don t control. As we move a lot of value into the Internet and have Internet commerce and begin buying and selling things, that is basically the only way of protecting either the transactions or where the goods are intellectual property the goods themselves. Before public-key cryptography, in order to be able to use cryptography with somebody, you had to share a secret with them, which is kind of an intimate relationship for somebody you might never have met before. Public- key cryptography relaxed all of that and made it much easier to manage keys in a very diverse environment like Internet commerce, as opposed to the more traditional large but rather unified environments like the Department of Defense. Why do you think that more e-mails aren t using encryption or digital signatures? I think it has to do with the difficulty of the key management. The key point is that cryptography has someho
