Totally Random

摘要

Here's a random thought: "Everything we do to achieve privacy and security in the computer age depends on random numbers." So says Simon Cooper, an encryption expert and author of Building Internet Firewalls. Random number sequences have been around for 4,000 years, but never have they been in such demand. That's because they're the building blocks of cryptography. Every time you establish an SSL connection to, say, E*Trade, there's a string of digits working hard behind the scenes. As many as 368 bits of random data go into creating the connection ― 128 bits to make encryption keys, the rest for authentication codes and the prevention of replay attacks ― that's necessary whenever you send your credit card information over an ecommerce site's "secure server" or exchange medical records with your insurance company online. Even the secrecy of the messages whizzing between military commanders in the Middle East depends on random numbers.