Glossary
EIP-712
An Ethereum standard for structured, human-readable data signing — replaces opaque hex with typed objects that wallets can display to users before signing.
Before EIP-712, signing arbitrary data on Ethereum meant signing an opaque hash — the user had no way to verify what they were authorizing. EIP-712 introduces typed structured data: the data is defined by a type schema, signed deterministically based on its structure, and rendered by wallets in human-readable form.
The standard powers gasless approvals (Permit), off-chain order books (CoW Protocol, OpenSea), session keys, and almost any modern wallet signature flow. EIP-712's domain separator (chain ID, contract address, name, version) also prevents cross-deployment signature replay attacks.