Quote from: stwenhao on Today at 09:00:02 AM

Quote

What would be the use of that?

You have the curve equation in all cases: "y^2=x^3+b". So, to calculate x-value or y-value, you have that:

Code:

y^2=x^3+b
y=sqrt(x^3+b)
x^3=y^2-b
x=cbrt(y^2-b)

So, the most basic use case, is just to get a valid point on a curve. You pick x-value, and want to calculate y-value, or the other way around: for a given y-value, you want to get a valid x-value. And that means, when you generate a curve, you want to make those operations "easy". And I wonder, why it is the case in all three other curves, but doesn't work in case of secp224k1 specifically.

Quote

But p is outside the range of allowed scalars which is from 1 to n.

All point coordinates are in range from 1 to (p-1). And then, private keys are in range from 1 to (n-1), but n-value is calculated later, when you already know p-value.

What do you think can it be used for compute private key for public key I mean can it be used for break Ecdsa?