Post
Topic
Board Development & Technical Discussion
Re: y coordinate calculation (PUBLIC KEY BITCOIN)
by
BlackHatCoiner
on 06/09/2021, 12:48:13 UTC
32748224938747404814623910738487752935528512903530129802856995983256684603122**28948022309329048855892746252171976963317496166410141009864396001977208667916
What exactly are you trying to do here? It doesn't seem okay to me.

@_Counselor Thanks for the answers... yes, I'm calculating using only x. Maybe with some more advanced equation or other methods it is possible to define exactly the value of y with only x?
But, the only thing you need to define the value of y is x. @interiawp added you a code in which you can get one of the two values by knowing the other. If you wanted to know x, but having only y, then it's: x^3 = y^2 - 7.

To convert between Ys, you have to calculate y2 = (y1 - secp256k1.p) * -1. One of Y is even and another is odd.
Excuse me for the noob question:  Let's assume x3=1, which means y2=8. What's y? Will it be square root of 8?