Duo makes your single sign-on more secure by providing a "second factor" of authentication in addition to your password. Even if someone manages to get your password, they won't be able to access your account.
Before you begin: The initial set-up process must be done on a computer. You will need the device that you will be using to authenticate with you. This can be a mobile phone, a U2F token or a landline.
Step 1. Sign-up for Duo
Login to the following url: https://www.smith.edu/its/util/2fa/signup/Duo2FA.php
Step 2. Download the Duo app (Smartphone users only)
The app is free, but you will need your App Store password. Instructions
Step 3. Register your devices
After completing the sign up page, you will be prompted to register your devices.
Step 4. Add a second device
ITS highly recommends you register at least two authentication devices