diff --git a/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/domain/nip46/NostrConnectLoginUseCase.kt b/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/domain/nip46/NostrConnectLoginUseCase.kt
index 674a38219..6725ef332 100644
--- a/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/domain/nip46/NostrConnectLoginUseCase.kt
+++ b/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/domain/nip46/NostrConnectLoginUseCase.kt
@@ -213,6 +213,6 @@ object NostrConnectLoginUseCase {
     private fun generateSecret(): String {
         val bytes = ByteArray(32)
         SecureRandom().nextBytes(bytes)
-        return bytes.joinToString("") { "%02x".format(it) }
+        return bytes.toHexKey()
     }
 }
diff --git a/quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip47WalletConnect/LnZapPaymentRequestEventTest.kt b/quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip47WalletConnect/LnZapPaymentRequestEventTest.kt
index bc5af2432..271c2783b 100644
--- a/quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip47WalletConnect/LnZapPaymentRequestEventTest.kt
+++ b/quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip47WalletConnect/LnZapPaymentRequestEventTest.kt
@@ -21,6 +21,7 @@
 package com.vitorpamplona.quartz.nip47WalletConnect
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import com.vitorpamplona.quartz.nip01Core.crypto.KeyPair
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
 import kotlinx.coroutines.test.runTest
@@ -44,7 +45,7 @@ class LnZapPaymentRequestEventTest {
             val walletKeyPair = KeyPair()
             val clientSigner = NostrSignerInternal(clientKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val event =
                 LnZapPaymentRequestEvent.create(
@@ -68,7 +69,7 @@ class LnZapPaymentRequestEventTest {
             val walletKeyPair = KeyPair()
             val clientSigner = NostrSignerInternal(clientKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val request = GetBalanceMethod.create()
             val event =
@@ -92,7 +93,7 @@ class LnZapPaymentRequestEventTest {
             val walletKeyPair = KeyPair()
             val clientSigner = NostrSignerInternal(clientKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val request = GetBalanceMethod.create()
             val event =
@@ -116,7 +117,7 @@ class LnZapPaymentRequestEventTest {
             val clientSigner = NostrSignerInternal(clientKeyPair)
             val walletSigner = NostrSignerInternal(walletKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val event =
                 LnZapPaymentRequestEvent.create(
@@ -139,7 +140,7 @@ class LnZapPaymentRequestEventTest {
             val clientSigner = NostrSignerInternal(clientKeyPair)
             val walletSigner = NostrSignerInternal(walletKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val request = MakeInvoiceMethod.create(5000L, "test payment")
             val event =
@@ -163,7 +164,7 @@ class LnZapPaymentRequestEventTest {
             val clientSigner = NostrSignerInternal(clientKeyPair)
             val walletSigner = NostrSignerInternal(walletKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val request = GetInfoMethod.create()
             val event =
@@ -191,7 +192,7 @@ class LnZapPaymentRequestEventTest {
             val walletSigner = NostrSignerInternal(walletKeyPair)
             val otherSigner = NostrSignerInternal(otherKeyPair)
             val walletServicePubkey: HexKey =
-                walletKeyPair.pubKey.joinToString("") { "%02x".format(it) }
+                walletKeyPair.pubKey.toHexKey()
 
             val event =
                 LnZapPaymentRequestEvent.create(
diff --git a/quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip05DnsIdentifiers/namecoin/ElectrumXClient.kt b/quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip05DnsIdentifiers/namecoin/ElectrumXClient.kt
index c56dd72b1..b0ba1d6b7 100644
--- a/quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip05DnsIdentifiers/namecoin/ElectrumXClient.kt
+++ b/quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip05DnsIdentifiers/namecoin/ElectrumXClient.kt
@@ -20,6 +20,7 @@
  */
 package com.vitorpamplona.quartz.nip05DnsIdentifiers.namecoin
 
+import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
@@ -277,7 +278,7 @@ class ElectrumXClient(
      */
     private fun electrumScriptHash(script: ByteArray): String {
         val digest = MessageDigest.getInstance("SHA-256").digest(script)
-        return digest.reversedArray().joinToString("") { "%02x".format(it) }
+        return digest.reversedArray().toHexKey()
     }
 
     /**