Two-factor authentication, or 2FA, confirms a user's identity via two different factors: something they know and something they have. Also known as multi-factor authentication, two-step verification, and two-step authentication, 2FA enhances security. This guide explains how to use two-factor authentication with sudo and SSH on Linux with Google Authenticator by configuring the Google Authenticator PAM module. Before you proceed with this guide, you need a deployed Linux cloud server. We recomme......