forks/go-ethereum
1
0
Fork 1
mirror of https://github.com/ethereum/go-ethereum.git synced 2026-07-24 21:56:43 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Update twist.go

Browse source
This commit is contained in:
Antonio Sanso 2025-06-20 11:00:48 +02:00 committed by GitHub
parent da8f1a872a
commit f8331e8b47
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 3 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
crypto/bn256/google/twist.go
View file

@ -67,7 +67,7 @@ func (c *twistPoint) Set(a *twistPoint) {
c.t.Set(a.t) c.t.Set(a.t)
} }
// IsOnCurve returns true iff c is on the curve where c must be in affine form. // IsOnCurve returns true iff c is on the curve and is in the correct subgroup, where c must be in affine form.
func (c *twistPoint) IsOnCurve() bool { func (c *twistPoint) IsOnCurve() bool {
pool := new(bnPool) pool := new(bnPool)
yy := newGFp2(pool).Square(c.y, pool) yy := newGFp2(pool).Square(c.y, pool)
@ -80,6 +80,8 @@ func (c *twistPoint) IsOnCurve() bool {
if yy.x.Sign() != 0 || yy.y.Sign() != 0 { if yy.x.Sign() != 0 || yy.y.Sign() != 0 {
return false return false
} }
// Subgroup check: multiply the point by the group order and
// verify that it becomes the point at infinity.
cneg := newTwistPoint(pool) cneg := newTwistPoint(pool)
cneg.Mul(c, Order, pool) cneg.Mul(c, Order, pool)
return cneg.z.IsZero() return cneg.z.IsZero()