Since 2016, Princeton has been using Duo for 2-factor authentication (2FA). Most users interact with Duo by way of the Duo Mobile application on a smartphone.

This page describes the process to configure and use Two-Factor Authentication (2FA) with the CS Department's Zimbra email service (which includes webmail, IMAP, POP, and ActiveSync access methods). The use of 2FA is important in limiting the negative impacts of compromised passwords.

This page is an extension of CS Guide's Secure Shell (SSH).

Duo 2FA is required for all SSH logins to Princeton University Computer Science research & computing servers. These include cycles.cs.princeton.edu (aka portal, soak/wash/rinse/spin), ionic.cs.princeton.edu, courselab.cs.princeton.edu, and armlab.cs.princeton.edu.