EIP-712 Typed Data Signing

Overview

EIP-712 defines a domain-separated method for encoding, hashing, and signing structured Ethereum data. Applications describe named types and fields, then combine the message hash with a domain containing context such as application name, version, chain ID, and verifying contract. Readable signing improves user understanding and reduces ambiguity, but a valid signature still authorizes exactly what the application verifies. Weak domains, missing nonces, unlimited deadlines, deceptive interfaces, or incorrect contract logic can enable replay or unintended permission.

Wallets should display every material field and domain clearly. Contracts must reconstruct hashes exactly, bind signatures to the correct chain and contract, enforce nonce and expiry, and validate the recovered signer. Integrators should never treat a typed-data signature as harmless login text without reviewing its effects. Teams adopting EIP-712 should track errata, compatibility changes, and the deployed software versions that enforce it. When evaluating EIP-712, a published standard does not prove universal adoption, safe implementation, or activation on a particular blockchain or payment network.

Operational records for EIP-712 should retain the version and configuration used for each relevant transaction or message. When evaluating EIP-712, this allows reproducible debugging when a later upgrade changes parsing, validation, signing, or interoperability behavior.

EIP-712 should be implemented against an exact document revision, status, and activation context. When evaluating EIP-712, draft, final, optional, and network-activated specifications have different authority, and similarly named deployments may support different subsets or extensions. Conformance to EIP-712 requires more than matching a field name or example. When evaluating EIP-712, implementations should validate normative requirements, encodings, error behavior, security conditions, and test vectors, including malformed and boundary inputs that ordinary happy-path tests miss.