YubiKey
also: Yubico Security Key, hardware security key
A hardware security key that generates time-based or challenge-response authentication codes, used to secure Linux system access and online accounts against unauthorized login.
A YubiKey is a small USB device manufactured by Yubico that implements strong two-factor authentication (2FA) and passwordless login. It stores cryptographic keys and can generate one-time passwords (OTP) or respond to authentication challenges without revealing secrets to the computer.
On Linux systems, YubiKeys work with tools like pam_u2f and pam_yubico to secure SSH login, sudo access, and system authentication. For example, you can configure your Linux server to require both your password and a YubiKey touch to grant access, making it extremely difficult for attackers to compromise your account even if they steal your password.
YubiKeys support multiple protocols including FIDO2, U2F, TOTP, and Yubico's proprietary OTP format. They work across Linux, macOS, Windows, and mobile platforms, making them a versatile hardware security solution for developers and system administrators.