diff --git a/packages/sdk/src/utils/encoding.ts b/packages/sdk/src/utils/encoding.ts
index 557c1a41..0473680b 100644
--- a/packages/sdk/src/utils/encoding.ts
+++ b/packages/sdk/src/utils/encoding.ts
@@ -1,4 +1,4 @@
-import { type Address, encodeAbiParameters, getAbiItem, type Hash, type Hex, parseAbiParameters, toHex } from "viem";
+import { type Address, encodeAbiParameters, getAbiItem, type Hash, type Hex, pad, parseAbiParameters, toHex } from "viem";
 
 import { SessionKeyModuleAbi } from "../abi/SessionKeyModule.js";
 import { getPeriodIdsForTransaction, type SessionConfig } from "../utils/session.js";
@@ -52,7 +52,7 @@ export const encodePasskeyModuleParameters = (passkey: { passkeyPublicKey: [Buff
       { type: "string", name: "expectedOrigin" },
     ],
     [
-      [toHex(passkey.passkeyPublicKey[0]), toHex(passkey.passkeyPublicKey[1])],
+      [pad(toHex(passkey.passkeyPublicKey[0])), pad(toHex(passkey.passkeyPublicKey[1]))],
       passkey.expectedOrigin,
     ],
   );
diff --git a/packages/sdk/src/utils/passkey.ts b/packages/sdk/src/utils/passkey.ts
index 68de54d1..264d9dd2 100644
--- a/packages/sdk/src/utils/passkey.ts
+++ b/packages/sdk/src/utils/passkey.ts
@@ -2,7 +2,7 @@ import { ECDSASigValue } from "@peculiar/asn1-ecc";
 import { AsnParser } from "@peculiar/asn1-schema";
 import { bigintToBuf, bufToBigint } from "bigint-conversion";
 import { Buffer } from "buffer";
-import { type Address, encodeAbiParameters, type Hex, toHex } from "viem";
+import { type Address, encodeAbiParameters, type Hex, pad, toHex } from "viem";
 
 enum COSEKEYS {
   kty = 1, // Key Type
@@ -324,7 +324,7 @@ export function passkeyHashSignatureResponseFormat(
     [
       toHex(base64UrlToUint8Array(passkeyResponse.authenticatorData)),
       toHex(base64UrlToUint8Array(passkeyResponse.clientDataJSON)),
-      [toHex(signature.r), toHex(signature.s)],
+      [pad(toHex(signature.r)), pad(toHex(signature.s))],
     ],
   );
   const fullFormattedSig = encodeAbiParameters(