Re: AES Galois Field Inverse

BRG <BRG@xxxxxxxxxxx> writes:
For those who like a programming challenge, can anyone come up with a
way of writing a set of C preprocessor operations that can provide an
inverse in the Galois field used for the AES sbox?

In other words I am looking for a C compile time field inversion
operation in GF(2^8) with the AES field representation.

I am interested in one that is likely to work on most compilers that are
in common use. I can do this in principle but the compiler I am using
(Microsoft VC++) runs out of heap space during evaluation.

So I am wondering if anyone can come up with a way that minimises the
preprocessor resource costs of such an evaluation.

Don't use cpp as your C pre-processor. Use M4, or a code generation
script in perl or python or ruby or C or whatever.

"Home taping is killing big business profits. We left this side blank
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/In God We Trust, Inc./.