# EIP-155

`account-signature.eip155.v1` verifies approval from an EVM account stored in
an ENS address record. Both the ENS authority and the target account approve
the same claim using the existing typed-data format.

## Supported Accounts

| Account                              | How approval is checked                                             |
| ------------------------------------ | ------------------------------------------------------------------- |
| Ordinary wallet (EOA)                | Recover the signer and compare it with the recorded address         |
| Deployed smart account               | Ask the account's ERC-1271 implementation to validate the signature |
| Account with EIP-7702 delegated code | Use ERC-1271 at the account address                                 |

Smart accounts can apply their own multisig, passkey, or other signing policies
through ERC-1271. Counterfactual proofs using ERC-6492 are not supported in this
version. See [signature rules](/implementers/signatures).

## Configure the Record

For an Ethereum address, publish the address under coin type `60` and its
descriptor under:

```text
verification[addr][60]
```

The descriptor can point to an envelope published over HTTPS:

```text
ensrv1 a=1 m=account-signature.eip155.v1 u=https://proofs.example/alice-eth.json
```

Other supported [proof locations](/implementers/proof-retrieval), including
inline proofs, are also allowed. This method does not use a proof key.

For other EVM chains, use the chain-specific coin type. The claim identifies
both the account and its chain. Approval for an account on Ethereum does not
verify the same address on Base or another chain.

## Create the Proof

1. Prepare the common claim for the name, current address record, authority,
   target chain, and validity period.
2. Obtain the ENS authority's approval as `authoritySignature`.
3. Obtain the target account's approval as `proof.targetSignature`.
4. Publish the complete envelope at `u`.

An ordinary wallet signs the full typed claim with `signTypedData`. The EVM
profile does not sign the digest's hexadecimal text as a message. A smart wallet
produces signature bytes that its account can validate through ERC-1271.

The two signatures may be identical when the same account fills both roles.
Both checks are still required, using the account state on each relevant chain.

## What Is Verified

The verifier checks the live record and ENS authority, then validates the target
account's approval on the target chain. Hosting a proof file is not evidence of
account control by itself.

A successful result has verification type `control`. It confirms approval of
this exact connection, not the account holder's legal identity or ownership of
every address in their wallet.

## Validity and Renewal

A claim may last at most 90 days. A positive result must be refreshed within
five minutes or any shorter applicable bound. Record changes, authority changes,
and changes to a smart account's signature policy require re-evaluation.

Renewal requires approval of the new claim from both sides. See
[Lifecycle](/docs/components/lifecycle).

## Implementer Guide

See [EIP-155 for implementers](/implementers/methods/account-signature/eip155)
for target derivation, proof encoding, chain snapshots, and verification rules.