Sign-In with Ethereum (EIP-4361)
SIWE is the Web3 equivalent of Sign-In with Google. Enables dApps to authenticate users via their Ethereum address without a password, using their wallet signature.
What It Defines
Defines a standard message format and verification process for authenticating with an Ethereum account (EOA or smart contract wallet). Message includes domain, address, statement, URI, chain ID, nonce, and expiry. Signed via EIP-712.
Canonical (Normative)
Convenient (Practical)
The Ethereum community's open process for proposing changes to the protocol. EIPs cover core protocol changes; ERCs (Ethereum Request for Comments) cover application-layer standards like token interfaces.
Related Specs
EIP-712 is the standard for secure off-chain message signing used in permit() flows, meta-transactions, and Sign-In with Ethereum. Prevents blind signing attacks.
DIDs are the foundation of self-sovereign identity (SSI) and Web3 identity. They underpin Verifiable Credentials, Sign-In with Ethereum, and many blockchain identity schemes.
Sign-in with Google/Apple/GitHub all use OIDC. If your app authenticates users via a third party, you're using OIDC whether you know it or not.