> Charles M. Hannum wrote: > > Most implementations of /dev/random (or so-called "entropy gathering daemons") > > rely on disk I/O timings as a primary source of randomness. This is based on > > a CRYPTO '94 paper[1] that analyzed randomness from air turbulence inside the > > drive case. At the last place at which I worked, a few years ago, a "random number" was generated, and used in a FIPS 140-1 compliant encryption device, by capturing 128 ethernet frames in sequence from the local in-house network, gathering the LSB from the arrival time of each frame, and using those values to generate an encryption key. This was part of the "activation sequence" which had to be done, once, on each such device. Any studies out there on the randomness of such a number? At first glance a non-deterministic network would seem to be able to generate a useful number for the key. - Bob Foxworth, GSEC, CISSP