"Has anyone given any thought to generating random numbers by counting particle emissions from a radioactive source? This might be more reliably random than using purely electronic means." The Exploratorium has a display - a large set of charged plates by which one can see spark trails elicited by high-energy particles as they pass through the array - which has often intrigued me as a source of noise ... what is more unpredictable and harder to spoof than a cosmic ray detector ? Especially if you use not only the timing of the particle's arrival, but also its direction through the array of plates, as inputs to the random number generator ... Air pressure, temperature and other ambient factors in the environment could also be used as sources for unpredictable inputs ( measuring very small variations, IE, millions of a degree or some such ). -- richard ===== -- richard childers rchilder@us.oracle.com 1 415 506 2411 oracle data center -- unix systems & network administration Klein flask for rent. Inquire within.