The login form is gone. No password prompt. No reset emails. Just a clean, instant handshake between your identity and the service you want. This is passwordless authentication, and it’s changing the security model for modern apps.
A passwordless authentication security review starts with the attack surface. Password databases are common breach targets. Remove passwords, and you erase an entire class of credential theft. Phishing loses power because there’s no secret for attackers to steal. Credential stuffing becomes irrelevant.
Most passwordless systems rely on cryptographic keys, device-bound credentials, or one-time login links. WebAuthn delivers strong public‑key cryptography tied to the user’s hardware. Magic links and passcodes shift trust to an email or SMS channel, which demands review of those channels’ security. OAuth and OpenID Connect can enable passwordless flows by delegating identity to an external provider.
Security review must inspect each component. Key storage must be tamper-proof. Authentication endpoints must enforce strict origin checks. Replay protection, nonce validation, and TLS remain non‑negotiable. Device enrollment flows must confirm user intent and prevent silent registration by malware or attacker‑controlled browsers.