Re: [tcpm] Minimum nonce length in draft-touch-tcpm-experimental-options

[Yoshifumi Nishida <[e-mail]>]

Hi,

On Mon, Feb 20, 2012 at 3:34 AM, SCHARF, Michael
<[e-mail]> wrote:
> Joe,
>
> The wording on the nonce length in draft-touch-tcpm-experimental-options
> may be a little bit unclear ("it MAY be as few as 16 bits if desired").
>
> Does that statement intend to say something like "MUST NOT be shorter
> than 16 bits long"? Or shall even a nonce of length 0 be allowed,
> provided that there are additional security mechanism such as checksums
> or digital signatures? In the latter case, existing use of the
> codepoints without nonce could be compliant to the recommendation,
> provided that there are other means to detect false positives.

I don't have strong opinion on this yet, but I personally think we
don't have to mention minimum length specifically in the draft.
However, I might prefer to put a little bit more stress in this regards, like,
   o It's implementor's responsibility to find good balance between
the overhead of magic number and the overhead to handle false
positive.
   o the draft doesn't guarantee anything even if an implementor
chooses longer magic number

Thanks,
--
Yoshifumi Nishida