Gang...

A twitter follower put me onto another elliptic curve that DJB 
has been exploring and appears to be endorsing.

There's NOTHING AT ALL WRONG with our currently chosen 25519 
curve, and SQRL/1.0 (the user-agent string) will use it. 

(I also learned that Ed25519 is what Apple chose several years 
ago for their own not-much-talked-about-in-detail security 
architecture for things like internal iOS device security
-- the need to write to locked devices -- iCloud, etc.)

But being able to move up gracefully to longer bit lengths in 
the infinite future -- where we would like SQRL to continue to 
exist -- is the most presently obvious need we might have for 
future versioning.

Whereas we're currently using a modulo 2^255-19, the next 
candidate curve uses 2^414-17.  Unlike our Curve25519, this one 
is referred to as Curve3617 because it uses the curve formula:

x^2+y^2 = 1+3617x^2y^2

And whereas our curve had a work attack factor of about 2^140, 
if I'm reading things right, this one appears to offer 2^205
.... so significantly more.

The trouble is it's new and not yet well supported.  Also, what 
we have now is fine.  But we'll be wanting to keep an eye on 
this one.

To that end, here's a sub-site of Dan's I hadn't encountered 
before:

http://safecurves.cr.yp.to/index.html

And some interesting related links:

> http://cr.yp.to/talks/2013.05.31/slides-dan+tanja-20130531-4x3.pdf

> http://cr.yp.to/talks/2013.09.16/slides-djb-20130916-a4.pdf

> http://silentcircle.wordpress.com/2013/10/17/this-one-goes-to-414/

-- 
________________________________________________________________
Steve.               Working on moving the SQRL project forward.