# Messages & Authentication

## Overview

Ethereum accounts prove ownership and intent off-chain by signing structured messages.
Ox provides primitives for every common signing envelope: [ERC-191](https://eips.ethereum.org/EIPS/eip-191)
personal messages, [EIP-712](https://eips.ethereum.org/EIPS/eip-712) typed data,
[Sign-In with Ethereum](https://eips.ethereum.org/EIPS/eip-4361) authentication, and the
[ERC-6492](https://eips.ethereum.org/EIPS/eip-6492)/[ERC-8010](https://eips.ethereum.org/EIPS/eip-8010)
wrappers used by smart accounts.

```ts twoslash
import { Hex, PersonalMessage, Secp256k1 } from 'ox'

// Compute the EIP-191 payload for a message.
const payload = PersonalMessage.getSignPayload(Hex.fromString('hello world'))

// Sign the payload.
const signature = Secp256k1.sign({ payload, privateKey: '0x...' })

// Recover the signer.
const signer = Secp256k1.recoverAddress({ payload, signature })
```

## Guides

<Cards>
  <Card icon="lucide:signature" title="Sign Personal Messages (EIP-191)" description="Compute EIP-191 sign payloads, sign, and recover signers." to="/guides/messages/personal-messages" />

  <Card icon="lucide:scroll-text" title="Sign Typed Data (EIP-712)" description="Hash and sign EIP-712 structured data." to="/guides/messages/typed-data" />

  <Card icon="lucide:fingerprint" title="Sign-In with Ethereum (SIWE)" description="Authenticate users with signed EIP-4361 messages." to="/guides/messages/siwe" />

  <Card icon="lucide:shield-check" title="Smart Account Signatures (6492/8010)" description="Wrap signatures for counterfactual and delegated accounts." to="/guides/messages/smart-account-signatures" />
</Cards>