Security Key
A small physical hardware device used as a strong second factor to verify your identity when logging in.
A security key↗ is a small physical hardware device, often shaped like a USB drive, that you plug in or tap to verify your identity when logging into an account, serving as a strong second authentication↗ factor alongside your password. Unlike a code sent by text message, a security key can't be intercepted remotely since it requires physical possession of the device.
Security keys that support the FIDO2/WebAuthn standard are also resistant to phishing↗, because the key cryptographically verifies it's talking to the genuine website and simply won't respond to a convincing fake one. This makes them one of the strongest widely available protections against account takeover↗.