Don Davis, of MIT Project Athena, did some research a number of years back on getting good (physical) randomness out of a unix workstation. If I recall correctly, the general idea was to look for trends and biases, find explanations for them, and then filter them out or normalize against them. Sources of "real" nondeterminism came from things like variations in hard drive behavior (such as actual seek time, which shows up indirectly in the paging system because it does or does not cause time delays due to missed sectors...) I don't have a reference handy, but if noone comes up with one I'll send him email and see if he has it online. In other words, 'ps -laxww' itself is relatively useless -- but the underlying data does actually have randomness; you may have to dig pretty hard for it, though. _Mark_ SUB: Re: ps -laxww for randmoness? SUM: <tytso>, tytso (Theodore Ts'o)->avalon@coombs.anu.edu.au, cypherpunks@toad.com From: avalon@coombs.anu.edu.au (Darren Reed) Date: Wed, 16 Dec 92 2:30:49 EST Has anyone tried using the microsecond counter from unix as a random source ? Its obviously *not* going to be good if you want a continuous stream of random numbers, but if you need them just 'every now and then', what about it ? This should be in an FAQ: Unixes have different levels of granularity in the microsecond counter; some systems may only have a 10 ms (that's 10000 microsecond) resolution to their clock. So you can't necessarily depend on a getting lot of bits of randomness from this method. - Ted