Messages in this thread | | | From | (H. Peter Anvin) | Subject | Re: Intel 810 Random Number Generator | Date | 25 Jan 2000 18:35:20 -0800 |
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Followup to: <200001260115.UAA08354@tsx-prime.MIT.EDU> By author: "Theodore Y. Ts'o" <tytso@MIT.EDU> In newsgroup: linux.dev.kernel > > P.S. If you look at the Jun and Kocher paper (thanks to Colin Plumb for > giving me a pointer to it: > > http://developer.intel.com/design/security/rng/CRIwp.htm > > It's clear that there is a hardware whitener (a von Neumann bias > eliminator) to remove 0 vs 1 biases. There are hints that it's > possible to turn off the whitener, so that you get access to the raw > stream of bits from the RNG before any whitening is done. > Unfortunately, how to actually do this (probably some kind of debug > mode) doesn't seem to be published anywhere. If any one knows how to do > this, please let me know. Ideally, if the software is going to be doing > real-time verification of the RNG's soundness, it should be doing so on > the pre-whitened data stream. As an example, the following string of > numbers is anything but random: > > 1 2 3 4 5 6 7 8 9 10 > > However, if this is run through a MD5 or SHA whitener, the result would > *look* random, even though the source material is anything but random. > So you really want to look for patters and do any analysis on the raw > data stream. > > So, if anyone can figure out (and tell me) how to turn off the 810's > hardware whitener circuits, that would be really useful. Thanks!! >
What a waste of transistors! The hardware whitener probably takes far more transistors than the circuit itself, and it's not even a good idea...
-hpa -- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot."
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