[curves] Fwd: Crash Course on ECC poster

Tanja Lange tanja at hyperelliptic.org
Tue Jul 7 23:01:04 PDT 2015

Dear Tony,
> Would appreciate technical feedback on it. If you'd like to suggest copy
> changes, please consider design constraints (i.e. available room on the page).
I've seen 'clock arithmetic' used for computing mod p but I think 
Dan Bernstein and I were introducing 'clock crypto' for real clocks.
Of course you're  'clock crypto' any way you want but I find it to
be confusing with our way of presenting elliptic curves via clocks,
where we use proper arithmetic on the clock (=circle). For our 
presentation the comment about 'distorted clocks' makes sense, I 
don't understand what it means if you take the clock to be just the
integers mod some prime.

Also the comment of 'adding up the hours on the crypto clock' fits
with the additive description of our clock crypto but not with your
multiplicative description.

>From teaching ECC for years I think that Edwards curves are much 
easier to understand than Weierstrass curves -- in particular once
you don't just concentrate on the one main case; anybody looking 
at the 'Point addition over real numbers for long enough will come
up with points A and B which they cannot add.

Minor nitpick: 'modulo a prime field' -> 'modulo a prime' or 'over a
prime field' (didn't do  full read but this one jumped out).

All the best

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