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Re: Bignums
I believe the real issue is which format is used by various crypto
libraries, where bignums will be used. I can think of RSAREF, BSAFE and
crypto++. When I fill in a public key for one of these libraries to use, I
would like to use memcpy rather than a byte-reversing for() loop.
BSAFE, at least, takes most significant byte first (in lowest address).
I assume RSAREF does as well.
I haven't looked inside crypto++ for this.
I grant that it is more efficient to have the least significant byte in the
least address. I suspect that these libraries actually swap bytes
internally. However, we are presented with a programmer's interface, at
least for BSAFE, in which the most significant byte is first. If we encode
bignums as least significant byte first, then we are forced to byte-swap
whenever we use them.
- Carl
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