Glossary
Passkey
A FIDO2 / WebAuthn credential bound to a device and biometric — increasingly used by smart-contract wallets as a seedphrase-less authentication factor.
Passkeys are the FIDO2 / WebAuthn standard's replacement for passwords: a public-key credential bound to the user's device and unlocked with a biometric or PIN. The private key never leaves the secure enclave.
Smart-contract wallets (Coinbase Smart Wallet, Safe Smart Account modules, several ERC-4337 implementations) can use passkeys as a signer instead of an ECDSA seed phrase. The result is a wallet that behaves like a normal Web2 sign-in but still controls on-chain assets cryptographically.