Re: [Cfrg] revised requirements for new curves

["Paterson, Kenny" <[e-mail]>]

Hi Stephen,

On 08/09/2014 15:42, "Stephen Farrell" <[e-mail]> wrote:

>Hiya,
>
>Good job and good to see this progressing towards completion.
>Thanks for both.
>
>On 08/09/14 11:23, Paterson, Kenny wrote:
>> 
>> SE5. Required: each set of curve parameters should be generated by a
>> well-defined procedure that allows only a limited and quantified amount
>>of
>> flexibility. If the selected procedure involves the choice of an initial
>> seed, then the seed will be selected by multiple independent parties
>>using
>> a procedure having the property that no collusion of all but one or
>>fewer
>> of the parties can exert any control over the chosen seed. [RC]
>
>A clarification question: the above reads a bit like the result
>has to be a curve that hasn't yet been documented. I assume that
>its ok if e.g. 25519 and/or one of msft's are picked and that this
>is not meant to rule those out.

That's correct - it's not meant to rule these out. The intention is that,
for a specific, existing curve like Curve25519 or one of the MSR curves,
this requirement would mean the publication of a clear selection rationale
and an evaluation of how much flexibility was exercised during the
selection. 

>It might be worth stating that e.g.
>along the lines of "Note that SE5 does not rule out selection of
>an already documented curve or curves should there be consensus
>that this requirement has been met sufficiently."

OK, this could certainly be added.

>
>If you do mean to rule those out, then I think that really would
>need to be crystal clear.
>
>Other than that:
>
>On IN1 and IN2 I agree with William's comment. And since that
>is to the effect that those don't help or hinder selections
>I'm ok with the text as-is.

OK, good to know.

>On IP1, I do agree with the intent, but that might need to be
>reworded to keep everyone happy - one can never know for sure
>that royalty-free anything is possible. But I'm ok with the
>wording as-is, since adding the equivalent of "as far as its
>possible to know" doesn't matter so much given that CFRG cannot
>afaik yet do the impossible;-)

Understood. So some fine-tuning might be merited here.

Cheers

Kenny 

>
>Ta,
>S.