From b96f5d728d52c4478f8e686831031accc9da19d3 Mon Sep 17 00:00:00 2001
From: Irfan Bozkurt <irfanbozkurt123@gmail.com>
Date: Sun, 4 Oct 2026 22:53:44 -0400
Subject: [PATCH] Reject neutral r in schnorr

---
 signature/schnorr/schnorr.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/signature/schnorr/schnorr.go b/signature/schnorr/schnorr.go
index b18b345..9d70aac 100644
--- a/signature/schnorr/schnorr.go
+++ b/signature/schnorr/schnorr.go
@@ -197,7 +197,11 @@ func IsSchnorrSignatureValid(pubKey, hashedMsg gFp5.Element, sig Signature) bool
 		return false
 	}
 
-	rV := curve.MulAddG(pubKeyWs, sig.S, sig.E).Encode() // r_v = s*G + e*pk
+	r := curve.MulAddG(pubKeyWs, sig.S, sig.E) // r = s*G + e*pk
+	if r.IsNeutral() {
+		return false
+	}
+	rV := r.Encode()
 
 	preImage := make([]g.GoldilocksField, 5+5)
 	copy(preImage[:5], rV[:])