Cosmic microwave background radiation can be used to generate large random numbers

New Scientist : One of the primary methods used to encrypt information involves the generation of large, nonreproducible random numbers that serve as the key. Because purely numerical algorithms can be reproduced, physical processes are often used as the basis for the keys. Now Jeffrey Lee and Gerald Cleaver of Baylor University in Waco, Texas, have shown that the cosmic microwave background (CMB) radiation left over from the Big Bang can be one of those processes. The reason the CMB works as a random-number generator is that measurements made by one observer of the strength of the signal from a specific area of the sky can never be duplicated exactly by another observer, even when made in exactly the same way at exactly the same time. Several measurements can then be combined to generate a large random number. Because of the expense and logistics involved in operating a radio telescope, however, only governments or large organizations would have the necessary resources to use cosmology as an encryption method.