Encrypt secrets in the afterglow of the big bang

摘要

If you've got a message to keep safe, look to the skies. You could use the afterglow of the big bang to make encryption keys - all you need is a radio telescope. The security of many systems relies on generating large random numbers to act as keys to encrypt information. Computers can use algorithms to spa wn these keys, but they aren't truly random, so another computer armed with the same algorithm could potentially duplicate the key. An alternative is to rely on physical randomness, like the weather, the thermal noise on a chip or the timing of someone's keystrokes. Now Jeff rey Lee and Gerald Cleaver at Baylor University in Waco, Texas, have taken this to the extreme by suggesting we use the thermal radiation left over from the big bang - the cosmic microwave background.