From da283147ec0476a0b84a3cbe54a606e73fcb3151 Mon Sep 17 00:00:00 2001
From: Eugene Zagidullin <eugene@ecadlabs.com>
Date: Wed, 1 Apr 2026 23:56:48 +0300
Subject: [PATCH] MLDSA44PublicKey.Hash() returned incorrect type leading to a
 wrong b58 prefix

---
 crypt/crypt_regression_test.go | 48 ++++++++++++++++++++++++++++++++++
 key.go                         |  2 +-
 2 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 crypt/crypt_regression_test.go

diff --git a/crypt/crypt_regression_test.go b/crypt/crypt_regression_test.go
new file mode 100644
index 0000000..894d164
--- /dev/null
+++ b/crypt/crypt_regression_test.go
@@ -0,0 +1,48 @@
+package crypt
+
+import (
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/elliptic"
+	"crypto/rand"
+	"testing"
+
+	"github.com/cloudflare/circl/sign/mldsa/mldsa44"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/ecadlabs/goblst/minpk"
+	"github.com/ecadlabs/gotez/v2"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPKHType(t *testing.T) {
+	t.Run("Ed25519", func(t *testing.T) {
+		p, _, _ := ed25519.GenerateKey(rand.Reader)
+		pub := Ed25519PublicKey(p)
+		_, ok := pub.Hash().(*gotez.Ed25519PublicKeyHash)
+		require.True(t, ok, "public key hash has type *gotez.Ed25519PublicKeyHash")
+	})
+	t.Run("Secp256k1", func(t *testing.T) {
+		k, _ := ecdsa.GenerateKey(secp256k1.S256(), rand.Reader)
+		pub := (*ECDSAPublicKey)(&k.PublicKey)
+		_, ok := pub.Hash().(*gotez.Secp256k1PublicKeyHash)
+		require.True(t, ok, "public key hash has type *gotez.Secp256k1PublicKeyHash")
+	})
+	t.Run("P256", func(t *testing.T) {
+		k, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+		pub := (*ECDSAPublicKey)(&k.PublicKey)
+		_, ok := pub.Hash().(*gotez.P256PublicKeyHash)
+		require.True(t, ok, "public key hash has type *gotez.P256PublicKeyHash")
+	})
+	t.Run("BLS", func(t *testing.T) {
+		k, _ := minpk.GenerateKey(rand.Reader)
+		pub := (*BLSPublicKey)(k.PublicKey())
+		_, ok := pub.Hash().(*gotez.BLSPublicKeyHash)
+		require.True(t, ok, "public key hash has type *gotez.BLSPublicKeyHash")
+	})
+	t.Run("MLDSA44", func(t *testing.T) {
+		p, _, _ := mldsa44.GenerateKey(rand.Reader)
+		pub := (*MLDSA44PublicKey)(p)
+		_, ok := pub.Hash().(*gotez.MLDSA44PublicKeyHash)
+		require.True(t, ok, "public key hash has type *gotez.MLDSA44PublicKeyHash")
+	})
+}
diff --git a/key.go b/key.go
index 6d7e6a1..c5b2ba1 100644
--- a/key.go
+++ b/key.go
@@ -341,7 +341,7 @@ func (pk *MLDSA44PublicKey) Hash() PublicKeyHash {
 		panic(err)
 	}
 	digest.Write(pk[:])
-	var out BLSPublicKeyHash
+	var out MLDSA44PublicKeyHash
 	copy(out[:], digest.Sum(nil))
 	return &out
 }