Fix G.y parity in sage code

2021-10-20 10:14:13 -04:00 · 2021-10-20 10:14:13 -04:00 · 044d956305
parent 9526874d14
commit 044d956305
1 changed files with 3 additions and 0 deletions
--- a/sage/secp256k1_params.sage
+++ b/sage/secp256k1_params.sage
@ -9,6 +9,9 @@ C = EllipticCurve([F(0), F(7)])

 """Base point of secp256k1"""
 G = C.lift_x(0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798)
+if int(G[1]) & 1:
+    # G.y is even
+    G = -G

 """Prime order of secp256k1"""
 N = C.order()