Subject: [COSE] Review of draft-ietf-cose-hash-sig-00

From: Jim Schaad <[email-masked]>
Date: Fri, 15 Feb 2019 22:27:19 -0800

Russ,

I don't remember when the last time I looked at this was, but since I have
been reviewing the version over in lamps, look at all of those things and
apply here.  I tried not to duplicating them below.  Please copy forward as
is reasonable.

1.  I am trying to create an example message for you, but I am having
problems with getting a running implementation based on the ID in CFRG.  One
of my biggest issues is that the test vectors are completely insufficient if
there are problems, and apparently I have a problem.

2.  The following statement seems a bit weird:  "The hash-based signature
algorithm supports five values for this parameter: h=5; h=10; h=15; h=20;
and h=25".  Would it not be better to say it along the lines of "Currently
there are five values registered for this parameter:..."

3.  You do not seem to have consistency between section 4 and the IANA
considerations wrt 'HSS-LMS' vs 'HASHSIG-HSS-LMS'

4.  I find it very interesting that in this document you do not have the
extra hash step that is present in the lamps document.  Specifically this
always uses the "direct" signature algorithm that I proposed over there.

Jim