From f7f57d29d43704cb49a3154da044f31970875f04 Mon Sep 17 00:00:00 2001
From: bigbear <155267841+aso20455@users.noreply.github.com>
Date: Mon, 13 Apr 2026 13:57:11 +0200
Subject: [PATCH] crypto/bn256: fix comment in MulXi (#34659)
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The comment formula showed (i+3) but the code multiplies by 9 (Lsh 3 +
add = 8+1).
This was a error when porting from upstream golang.org/x/crypto/bn256
where ξ=i+3.
Go-ethereum changed the constant to ξ=i+9 but forgot to update the inner
formula.
---
 crypto/bn256/google/gfp2.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/bn256/google/gfp2.go b/crypto/bn256/google/gfp2.go
index 3981f6cb4f..394ef83548 100644
--- a/crypto/bn256/google/gfp2.go
+++ b/crypto/bn256/google/gfp2.go
@@ -153,7 +153,7 @@ func (e *gfP2) MulScalar(a *gfP2, b *big.Int) *gfP2 {
 
 // MulXi sets e=ξa where ξ=i+9 and then returns e.
 func (e *gfP2) MulXi(a *gfP2, pool *bnPool) *gfP2 {
-	// (xi+y)(i+3) = (9x+y)i+(9y-x)
+	// (xi+y)(i+9) = (9x+y)i+(9y-x)
 	tx := pool.Get().Lsh(a.x, 3)
 	tx.Add(tx, a.x)
 	tx.Add(tx, a.y)