I am working on a semi-experimental hardware RNG project. I note that the publically available designs, e.g. http://willware.net:8080/hw-rng.html or http://world.std.com/~reinhold/waynesrngcomp.gif or the others listed at http://www.std.com/~reinhold/truenoise.html all use semiconductor junction noise as the source -- diode or transistor avalanche noise.
But all the modern commercial designs with which I'm familiar (which include the Intel, the Hifn, one Motorola design, and some others that are not publically documented) are all multiple-oscillator designs, in which some number (usually 2 or 3) of undisciplined oscillators of close design frequency drift against one another, and an ADC is used to sample the resulting output waveform. I cannot find any public, rigorous discussion of why such a design might be preferable to the semiconductor noise type of design -- but I have to assume the people designing the commercial sources have all converged on similar designs for _some_ reason. Can someone point me to a discussion of the advantages or disadvantages of either design type in the literature? I am not interested in the theoretical advantages of other, costlier sources such as radioactive-decay or "more direct" (than junction noise) quantum or thermal noise sources; I just want to understand why all the public domain designs are of one type, and all the commercial designs of the other. -- Thor Lancelot Simon [EMAIL PROTECTED] "We cannot usually in social life pursue a single value or a single moral aim, untroubled by the need to compromise with others." - H.L.A. Hart --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]