What equation suitable for generation of a public key is used for Edwards curve Ed25519
?
The problem is the following – info on Edwards Elliptic Curve on Wikipedia page presents an equation y^2 + x^2 = 1 + d * y^2 * x^2
that doesn't allow us to plot a curve depicted on the first picture.
So, what equation is used for Ed25519
? This one?
y^2 + x^2 = 1 - d * y^2 * x^2
Or this one?
y^2 + x^2 = 1 + d * y^2 * x^2
I haven't found any documentation covering this topic.