diff --git a/packages/message-encryption/src/index.ts b/packages/message-encryption/src/index.ts
index cd02baaa55..2f59584acc 100644
--- a/packages/message-encryption/src/index.ts
+++ b/packages/message-encryption/src/index.ts
@@ -1,5 +1,3 @@
-import * as secp from "@noble/secp256k1";
-import { concat, hexToBytes } from "@waku/byte-utils";
 import {
   DecodedMessage as DecodedMessageV0,
   Decoder as DecoderV0,
@@ -14,25 +12,22 @@ import type {
 } from "@waku/interfaces";
 import debug from "debug";
 
-import { Symmetric } from "./constants.js";
-import * as ecies from "./crypto/ecies.js";
 import {
   generatePrivateKey,
   generateSymmetricKey,
   getPublicKey,
-  keccak256,
-  randomBytes,
-  sign,
 } from "./crypto/index.js";
-import * as symmetric from "./crypto/symmetric.js";
+import {
+  decryptAsymmetric,
+  decryptSymmetric,
+  encryptAsymmetric,
+  encryptSymmetric,
+  postCipher,
+  preCipher,
+} from "./waku_payload.js";
 
 const log = debug("waku:message:version-1");
 
-const FlagsLength = 1;
-const FlagMask = 3; // 0011
-const IsSignedMask = 4; // 0100
-const PaddingTarget = 256;
-const SignatureLength = 65;
 const OneMillion = BigInt(1_000_000);
 
 export { generatePrivateKey, generateSymmetricKey, getPublicKey };
@@ -287,227 +282,3 @@ export function createSymDecoder(
 ): SymDecoder {
   return new SymDecoder(contentTopic, symKey);
 }
-
-function getSizeOfPayloadSizeField(message: Uint8Array): number {
-  const messageDataView = new DataView(message.buffer);
-  return messageDataView.getUint8(0) & FlagMask;
-}
-
-function getPayloadSize(
-  message: Uint8Array,
-  sizeOfPayloadSizeField: number
-): number {
-  let payloadSizeBytes = message.slice(1, 1 + sizeOfPayloadSizeField);
-  // int 32 == 4 bytes
-  if (sizeOfPayloadSizeField < 4) {
-    // If less than 4 bytes pad right (Little Endian).
-    payloadSizeBytes = concat(
-      [payloadSizeBytes, new Uint8Array(4 - sizeOfPayloadSizeField)],
-      4
-    );
-  }
-  const payloadSizeDataView = new DataView(payloadSizeBytes.buffer);
-  return payloadSizeDataView.getInt32(0, true);
-}
-
-function isMessageSigned(message: Uint8Array): boolean {
-  const messageDataView = new DataView(message.buffer);
-  return (messageDataView.getUint8(0) & IsSignedMask) == IsSignedMask;
-}
-
-/**
- * Proceed with Asymmetric encryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
- * The data MUST be flags | payload-length | payload | [signature].
- * The returned result  can be set to `WakuMessage.payload`.
- *
- * @internal
- */
-export async function encryptAsymmetric(
-  data: Uint8Array,
-  publicKey: Uint8Array | string
-): Promise<Uint8Array> {
-  return ecies.encrypt(hexToBytes(publicKey), data);
-}
-
-/**
- * Proceed with Asymmetric decryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
- * The returned data is expected to be `flags | payload-length | payload | [signature]`.
- *
- * @internal
- */
-export async function decryptAsymmetric(
-  payload: Uint8Array,
-  privKey: Uint8Array
-): Promise<Uint8Array> {
-  return ecies.decrypt(privKey, payload);
-}
-
-/**
- * Proceed with Symmetric encryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
- *
- * @param data The data to encrypt, expected to be `flags | payload-length | payload | [signature]`.
- * @param key The key to use for encryption.
- * @returns The decrypted data, `cipherText | tag | iv` and can be set to `WakuMessage.payload`.
- *
- * @internal
- */
-export async function encryptSymmetric(
-  data: Uint8Array,
-  key: Uint8Array | string
-): Promise<Uint8Array> {
-  const iv = symmetric.generateIv();
-
-  // Returns `cipher | tag`
-  const cipher = await symmetric.encrypt(iv, hexToBytes(key), data);
-  return concat([cipher, iv]);
-}
-
-/**
- * Proceed with Symmetric decryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
- *
- * @param payload The cipher data, it is expected to be `cipherText | tag | iv`.
- * @param key The key to use for decryption.
- * @returns The decrypted data, expected to be `flags | payload-length | payload | [signature]`.
- *
- * @internal
- */
-export async function decryptSymmetric(
-  payload: Uint8Array,
-  key: Uint8Array | string
-): Promise<Uint8Array> {
-  const ivStart = payload.length - Symmetric.ivSize;
-  const cipher = payload.slice(0, ivStart);
-  const iv = payload.slice(ivStart);
-
-  return symmetric.decrypt(iv, hexToBytes(key), cipher);
-}
-
-/**
- * Computes the flags & auxiliary-field as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
- */
-function addPayloadSizeField(msg: Uint8Array, payload: Uint8Array): Uint8Array {
-  const fieldSize = computeSizeOfPayloadSizeField(payload);
-  let field = new Uint8Array(4);
-  const fieldDataView = new DataView(field.buffer);
-  fieldDataView.setUint32(0, payload.length, true);
-  field = field.slice(0, fieldSize);
-  msg = concat([msg, field]);
-  msg[0] |= fieldSize;
-  return msg;
-}
-
-/**
- * Returns the size of the auxiliary-field which in turns contains the payload size
- */
-function computeSizeOfPayloadSizeField(payload: Uint8Array): number {
-  let s = 1;
-  for (let i = payload.length; i >= 256; i /= 256) {
-    s++;
-  }
-  return s;
-}
-
-function validateDataIntegrity(
-  value: Uint8Array,
-  expectedSize: number
-): boolean {
-  if (value.length !== expectedSize) {
-    return false;
-  }
-
-  return expectedSize <= 3 || value.findIndex((i) => i !== 0) !== -1;
-}
-
-function getSignature(message: Uint8Array): Uint8Array {
-  return message.slice(message.length - SignatureLength, message.length);
-}
-
-function getHash(message: Uint8Array, isSigned: boolean): Uint8Array {
-  if (isSigned) {
-    return keccak256(message.slice(0, message.length - SignatureLength));
-  }
-  return keccak256(message);
-}
-
-function ecRecoverPubKey(
-  messageHash: Uint8Array,
-  signature: Uint8Array
-): Uint8Array | undefined {
-  const recoveryDataView = new DataView(signature.slice(64).buffer);
-  const recovery = recoveryDataView.getUint8(0);
-  const _signature = secp.Signature.fromCompact(signature.slice(0, 64));
-
-  return secp.recoverPublicKey(messageHash, _signature, recovery, false);
-}
-
-/**
- * Prepare the payload pre-encryption.
- *
- * @internal
- * @returns The encoded payload, ready for encryption using {@link encryptAsymmetric}
- * or {@link encryptSymmetric}.
- */
-export async function preCipher(
-  messagePayload: Uint8Array,
-  sigPrivKey?: Uint8Array
-): Promise<Uint8Array> {
-  let envelope = new Uint8Array([0]); // No flags
-  envelope = addPayloadSizeField(envelope, messagePayload);
-  envelope = concat([envelope, messagePayload]);
-
-  // Calculate padding:
-  let rawSize =
-    FlagsLength +
-    computeSizeOfPayloadSizeField(messagePayload) +
-    messagePayload.length;
-
-  if (sigPrivKey) {
-    rawSize += SignatureLength;
-  }
-
-  const remainder = rawSize % PaddingTarget;
-  const paddingSize = PaddingTarget - remainder;
-  const pad = randomBytes(paddingSize);
-
-  if (!validateDataIntegrity(pad, paddingSize)) {
-    throw new Error("failed to generate random padding of size " + paddingSize);
-  }
-
-  envelope = concat([envelope, pad]);
-  if (sigPrivKey) {
-    envelope[0] |= IsSignedMask;
-    const hash = keccak256(envelope);
-    const bytesSignature = await sign(hash, sigPrivKey);
-    envelope = concat([envelope, bytesSignature]);
-  }
-
-  return envelope;
-}
-
-/**
- * Decode a decrypted payload.
- *
- * @internal
- */
-export function postCipher(
-  message: Uint8Array
-): { payload: Uint8Array; sig?: Signature } | undefined {
-  const sizeOfPayloadSizeField = getSizeOfPayloadSizeField(message);
-  if (sizeOfPayloadSizeField === 0) return;
-
-  const payloadSize = getPayloadSize(message, sizeOfPayloadSizeField);
-  const payloadStart = 1 + sizeOfPayloadSizeField;
-  const payload = message.slice(payloadStart, payloadStart + payloadSize);
-
-  const isSigned = isMessageSigned(message);
-
-  let sig;
-  if (isSigned) {
-    const signature = getSignature(message);
-    const hash = getHash(message, isSigned);
-    const publicKey = ecRecoverPubKey(hash, signature);
-    sig = { signature, publicKey };
-  }
-
-  return { payload, sig };
-}
diff --git a/packages/message-encryption/src/waku_payload.ts b/packages/message-encryption/src/waku_payload.ts
new file mode 100644
index 0000000000..a62b3e835d
--- /dev/null
+++ b/packages/message-encryption/src/waku_payload.ts
@@ -0,0 +1,239 @@
+import * as secp from "@noble/secp256k1";
+import { concat, hexToBytes } from "@waku/byte-utils";
+
+import { Symmetric } from "./constants.js";
+import * as ecies from "./crypto/ecies.js";
+import { keccak256, randomBytes, sign } from "./crypto/index.js";
+import * as symmetric from "./crypto/symmetric.js";
+
+import { Signature } from "./index";
+
+const FlagsLength = 1;
+const FlagMask = 3; // 0011
+const IsSignedMask = 4; // 0100
+const PaddingTarget = 256;
+const SignatureLength = 65;
+
+function getSizeOfPayloadSizeField(message: Uint8Array): number {
+  const messageDataView = new DataView(message.buffer);
+  return messageDataView.getUint8(0) & FlagMask;
+}
+
+function getPayloadSize(
+  message: Uint8Array,
+  sizeOfPayloadSizeField: number
+): number {
+  let payloadSizeBytes = message.slice(1, 1 + sizeOfPayloadSizeField);
+  // int 32 == 4 bytes
+  if (sizeOfPayloadSizeField < 4) {
+    // If less than 4 bytes pad right (Little Endian).
+    payloadSizeBytes = concat(
+      [payloadSizeBytes, new Uint8Array(4 - sizeOfPayloadSizeField)],
+      4
+    );
+  }
+  const payloadSizeDataView = new DataView(payloadSizeBytes.buffer);
+  return payloadSizeDataView.getInt32(0, true);
+}
+
+function isMessageSigned(message: Uint8Array): boolean {
+  const messageDataView = new DataView(message.buffer);
+  return (messageDataView.getUint8(0) & IsSignedMask) == IsSignedMask;
+}
+
+/**
+ * Proceed with Asymmetric encryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
+ * The data MUST be flags | payload-length | payload | [signature].
+ * The returned result  can be set to `WakuMessage.payload`.
+ *
+ * @internal
+ */
+export async function encryptAsymmetric(
+  data: Uint8Array,
+  publicKey: Uint8Array | string
+): Promise<Uint8Array> {
+  return ecies.encrypt(hexToBytes(publicKey), data);
+}
+
+/**
+ * Proceed with Asymmetric decryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
+ * The returned data is expected to be `flags | payload-length | payload | [signature]`.
+ *
+ * @internal
+ */
+export async function decryptAsymmetric(
+  payload: Uint8Array,
+  privKey: Uint8Array
+): Promise<Uint8Array> {
+  return ecies.decrypt(privKey, payload);
+}
+
+/**
+ * Proceed with Symmetric encryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
+ *
+ * @param data The data to encrypt, expected to be `flags | payload-length | payload | [signature]`.
+ * @param key The key to use for encryption.
+ * @returns The decrypted data, `cipherText | tag | iv` and can be set to `WakuMessage.payload`.
+ *
+ * @internal
+ */
+export async function encryptSymmetric(
+  data: Uint8Array,
+  key: Uint8Array | string
+): Promise<Uint8Array> {
+  const iv = symmetric.generateIv();
+
+  // Returns `cipher | tag`
+  const cipher = await symmetric.encrypt(iv, hexToBytes(key), data);
+  return concat([cipher, iv]);
+}
+
+/**
+ * Proceed with Symmetric decryption of the data as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
+ *
+ * @param payload The cipher data, it is expected to be `cipherText | tag | iv`.
+ * @param key The key to use for decryption.
+ * @returns The decrypted data, expected to be `flags | payload-length | payload | [signature]`.
+ *
+ * @internal
+ */
+export async function decryptSymmetric(
+  payload: Uint8Array,
+  key: Uint8Array | string
+): Promise<Uint8Array> {
+  const ivStart = payload.length - Symmetric.ivSize;
+  const cipher = payload.slice(0, ivStart);
+  const iv = payload.slice(ivStart);
+
+  return symmetric.decrypt(iv, hexToBytes(key), cipher);
+}
+
+/**
+ * Computes the flags & auxiliary-field as per [26/WAKU-PAYLOAD](https://rfc.vac.dev/spec/26/).
+ */
+function addPayloadSizeField(msg: Uint8Array, payload: Uint8Array): Uint8Array {
+  const fieldSize = computeSizeOfPayloadSizeField(payload);
+  let field = new Uint8Array(4);
+  const fieldDataView = new DataView(field.buffer);
+  fieldDataView.setUint32(0, payload.length, true);
+  field = field.slice(0, fieldSize);
+  msg = concat([msg, field]);
+  msg[0] |= fieldSize;
+  return msg;
+}
+
+/**
+ * Returns the size of the auxiliary-field which in turns contains the payload size
+ */
+function computeSizeOfPayloadSizeField(payload: Uint8Array): number {
+  let s = 1;
+  for (let i = payload.length; i >= 256; i /= 256) {
+    s++;
+  }
+  return s;
+}
+
+function validateDataIntegrity(
+  value: Uint8Array,
+  expectedSize: number
+): boolean {
+  if (value.length !== expectedSize) {
+    return false;
+  }
+
+  return expectedSize <= 3 || value.findIndex((i) => i !== 0) !== -1;
+}
+
+function getSignature(message: Uint8Array): Uint8Array {
+  return message.slice(message.length - SignatureLength, message.length);
+}
+
+function getHash(message: Uint8Array, isSigned: boolean): Uint8Array {
+  if (isSigned) {
+    return keccak256(message.slice(0, message.length - SignatureLength));
+  }
+  return keccak256(message);
+}
+
+function ecRecoverPubKey(
+  messageHash: Uint8Array,
+  signature: Uint8Array
+): Uint8Array | undefined {
+  const recoveryDataView = new DataView(signature.slice(64).buffer);
+  const recovery = recoveryDataView.getUint8(0);
+  const _signature = secp.Signature.fromCompact(signature.slice(0, 64));
+
+  return secp.recoverPublicKey(messageHash, _signature, recovery, false);
+}
+
+/**
+ * Prepare the payload pre-encryption.
+ *
+ * @internal
+ * @returns The encoded payload, ready for encryption using {@link encryptAsymmetric}
+ * or {@link encryptSymmetric}.
+ */
+export async function preCipher(
+  messagePayload: Uint8Array,
+  sigPrivKey?: Uint8Array
+): Promise<Uint8Array> {
+  let envelope = new Uint8Array([0]); // No flags
+  envelope = addPayloadSizeField(envelope, messagePayload);
+  envelope = concat([envelope, messagePayload]);
+
+  // Calculate padding:
+  let rawSize =
+    FlagsLength +
+    computeSizeOfPayloadSizeField(messagePayload) +
+    messagePayload.length;
+
+  if (sigPrivKey) {
+    rawSize += SignatureLength;
+  }
+
+  const remainder = rawSize % PaddingTarget;
+  const paddingSize = PaddingTarget - remainder;
+  const pad = randomBytes(paddingSize);
+
+  if (!validateDataIntegrity(pad, paddingSize)) {
+    throw new Error("failed to generate random padding of size " + paddingSize);
+  }
+
+  envelope = concat([envelope, pad]);
+  if (sigPrivKey) {
+    envelope[0] |= IsSignedMask;
+    const hash = keccak256(envelope);
+    const bytesSignature = await sign(hash, sigPrivKey);
+    envelope = concat([envelope, bytesSignature]);
+  }
+
+  return envelope;
+}
+
+/**
+ * Decode a decrypted payload.
+ *
+ * @internal
+ */
+export function postCipher(
+  message: Uint8Array
+): { payload: Uint8Array; sig?: Signature } | undefined {
+  const sizeOfPayloadSizeField = getSizeOfPayloadSizeField(message);
+  if (sizeOfPayloadSizeField === 0) return;
+
+  const payloadSize = getPayloadSize(message, sizeOfPayloadSizeField);
+  const payloadStart = 1 + sizeOfPayloadSizeField;
+  const payload = message.slice(payloadStart, payloadStart + payloadSize);
+
+  const isSigned = isMessageSigned(message);
+
+  let sig;
+  if (isSigned) {
+    const signature = getSignature(message);
+    const hash = getHash(message, isSigned);
+    const publicKey = ecRecoverPubKey(hash, signature);
+    sig = { signature, publicKey };
+  }
+
+  return { payload, sig };
+}