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Re: byte order



>>>>> "C" == C Harald Koch <chk@utcc.utoronto.ca> writes:

 C> ...
 C> In the case of DES, the inputs and outputs are all octet strings,
 C> at least in every definition I've seen.

Matt Thomas said much the same thing.

Part of the reason I raised the issue is that all the DES descriptions 
I have (such as FIPS 46, though admittedly the 1977 edition) describe
DES as a BLOCK cypher, operating on 64 bit blocks.  Neither FIPS 46
nor 1026 nor 1027, as far as I can find, describe any mapping of octet 
strings into DES blocks.

Another consideration is that I couldn't readily tell the byte order
of a popular DES implementation (the one by Eric Young); some of what
it does suggests it might be little endian, but the way it describes
the IP suggests that it may be big endian after all.

Unless there is a clear statement of the octet string mapping to DES
blocks in some existing document (if so, I'd appreciate a pointer) I
feel very strongly that this has to be added to the (3)DES transform
specs. 

	paul


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