Password-only SSH authentication is one of the most common — and most dangerous — security gaps in Linux server management. Attackers armed with credential lists and automated scripts can hammer your SSH port indefinitely. If your password is the only thing standing between them and root access, your environment is one breach away from a serious incident. Two-factor authentication (2FA) via Google Authenticator eliminates that single point of failure. Even if an attacker gets your password, they still need the time-based one-time code from your phone — a six-digit number...