Show Table of Contents
4.5. One-Time Passwords
One-time password (OTP) is a password that is valid for only one authentication session; it becomes invalid after use. Unlike traditional static passwords that stay the same for a longer period of time, OTPs keep changing. OTPs are used as part of two-factor authentication: the first step requires the user to authenticate with a traditional static password, and the second step prompts for an OTP issued by a recognized authentication token.
Authentication using an OTP combined with a static password is considered safer than authentication using a static password alone. Because an OTP can only be used for successful authentication once, even if a potential intruder intercepts the OTP during login, the intercepted OTP will already be invalid by that point.
One-Time Passwords in Red Hat Enterprise Linux
Red Hat Identity Management supports OTP authentication for IdM users. For more information, see the Linux Domain Identity, Authentication, and Policy Guide.

Where did the comment section go?
Red Hat's documentation publication system recently went through an upgrade to enable speedier, more mobile-friendly content. We decided to re-evaluate our commenting platform to ensure that it meets your expectations and serves as an optimal feedback mechanism. During this redesign, we invite your input on providing feedback on Red Hat documentation via the discussion platform.