From: cwedgwood@cybernet.co.nz (Chris Wedgwood)
Date: Tue, 22 Nov 94 10:11:22 PST
To: cypherpunks@toad.com
Subject: Re: Pentium bug and CRYPTO
Message-ID: <m0r9uNz-000SgBC@mserve>
MIME-Version: 1.0
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chris.claborne@sandiegoca.ncr.com writes:
[Will the following error (Re
[Pentium Floating Point Bug ... cause problems with PGP key generation or]
[any other normal operations with PGP or other crypto.]

It shouldn't effect PGP in the slightest. Its a bug that effects only
certain mantissa (23 are known so far) when doing a floating point divide
(double precision).

PGP doesn't use floating point for its big-numbers and it has no need for
double precision. Since most version of PGP compiled for Intel platforms
will be or the MS-DOS or Windows variety then it is very unlikely that even
floating point instructions will be used - emulations libraries will be used
instead for floating point. NT is a slightly different matter - but as I
said PGP doesn't use floating point for the key generation or ANY of the
RSA/IDEA code....

An interesting point about this rather obscure bug though. It won't effect
over 99% of all Pentium machines in use. It won't effect word, windows or
any of the other numerous programs that hold a large market share and
high-usage stats.... but people making a big deal out of this and demanding
fixes (I have heard new Pentiums don't do this and am going to test this
next week) could cost Intel millions potentially..... and I doubt whether it
would effect PovRay or whatever things people might actually use floating
point for anyways....

Serious scientific work could suffer severely, and since Intel boxes are good
power for dollar there are quite a few used in various places for intensive
calculations.... (e.g. seismic ray-tracing - but that done of 486-DX2-66
machine because here is NZ they are about half the price of a Pentium so are
even better value for money).

Chris