Re: [Cfrg] I-D Action: draft-nir-cfrg-chacha20-poly1305-01.txt

[Alyssa Rowan <[e-mail]>]

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On 13/03/2014 15:16, Ted Krovetz wrote:
>> So, for example, the input to chacha is a 256-bit key string,
>> 96-bit nonce string and 32-bit unsigned integer. The first thing
>> that happens in chacha is the key and nonce are split into 32-bit
>> unsigned integers by byte reversing each 32-bit chunk and then
>> interpreting each 32-bit chunk as an unsigned integer. Now we're
>> in the realm of integers, and the word endianess is never
>> mentioned.

Putting my programmer hat on for a moment, I find this wording rather
opaque, because of (as Mike mentions)…

On 13/03/2014 17:05, Mike Hamburg wrote:
> I say this because "interpreting each 32-bit chunk as an unsigned
> integer" is ambiguous.  The natural meaning is "according to the
> platform's endian" which is not what you want.

…this.

I'm not sure avoiding the term 'little-endian' when that's what people
will recognise as explicitly describing the byte order (well, _octet_
order, if you must) of the representation of an integer in memory
makes it any clearer.
- -- 
/akr
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