At 1:22 PM -0700 8/13/99, David Honig wrote:
>At 02:39 PM 8/11/99 -0400, Henry Spencer wrote:
>>
>>And will those hardware RNGs be subject to export control? Betcha they
>>will, assuming export control survives legal challenges. If this isn't
>>"enabling technology", I don't know what is...
>
>Hey, there are *legitimate* civilian uses for RNGs. For testing various
>kinds of communications gear. For true-random dithering. For monte-carlo
>verification. For soothing-sound generators to help you sleep...
It bothers me when people who are in favor of strong crypto automatically
assume that anything which makes strong crypto easier will automatically be
export controlled. This assertion is clearly wrong. The thing which most
makes strong crypto easier is the (slow) general purpose CPU. These have
never been export controlled.
We should proceed from the assumption that unless it is specifically
forbidden, it is permitted. For example, since strong authentication
(without privacy) is permitted, we should export it. Yes, it can be
perverted into providing privacy, but so can CPUs.
At 9:25 AM -0700 8/11/99, Theodore Y. Ts'o wrote:
>I've always thought there was a major opportunity for someone to come up
>with an ISA (or perhaps even a PCI) board which had one or more circuits
>(you want more than one for redundancy) that contained a noise diode
>hooked up to a digitizing circuit. As long as the hardware interface
>was open, all of the hard parts of a hardware RNG, could be done in
>software.
>
>Besides the whitner, the other thing that you really have to do (and
>which makes a hardware RNG harder than some people assume) are checks to
>make sure it is still functioning correctly, and to switch to another
>input source if one of the channels starts producing all zeros, or all
>ones, or some other noticeable pattern. (Something which would be
>*good* to do periodically is to run an FFT over the raw data sent out
>from the hardware RNG circuit, and make sure the power spectra doesn't
>show any obvious changes.)
The FIPS-140 tests are a good start for checking that the hardware is still
working.
Arnold Reinhold pointed out that sound cards are quite available and easy
to use as a source of entropy. I particularly like using the differences
between stereo microphones because it eliminates a lot of common-mode
interference. The big problem with sound cards and microphones is that a
Trojan horse could use them to listen in on conversations in the room. I
expect that there isn't much of interest to listen to in the typical server
room. People should probably avoid speaking passwords though.
-------------------------------------------------------------------------
Bill Frantz | The availability and use of secure encryption may |
Periwinkle | offer an opportunity to reclaim some portion of |
Consulting | the privacy we have lost. - B. FLETCHER, Circuit Judge |
