[messaging] sign(y) for Elligator2_p2r from X25519 u-points
torfone at ukr.net
Wed Mar 14 05:46:11 PDT 2018
I'm trying to adapt Elligator2 p2r() to the uNaCl X25519 library for embedded systems.
The original p2r() uses the sign(v) to select between sqrt(-u/(2(u+A))) and sqrt(-(u+A)/(2u))) .
But X25519 point has no v ( sign(v) is always assumed to be 0 ).
Can I use sign(v)=0 or must select the sign(v) randomly to get a completely random representation string of X25519 u-point with p2r()?
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Messaging