Any ideas?
How do you know if PubKey prefix = 02?
you can do this:
if (isOdd == 0) { // 02
_GetHash160Comp(px, isOdd, (uint8_t *)h);
CHECK_POINT(h, incr, 0, true);
}
In addition, you will have to calculate the Y coordinate when adding points. Look at my mod 12. I removed everything unnecessary there in GPU.