> For the complete documentation index, see [llms.txt](https://docs.zipwire.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zipwire.io/fundamentals/security/authenticator-mobile-apps.md). # Authenticator mobile apps ### **How to set up an authenticator app for 2FA** Two-factor authentication (2FA) adds an extra layer of security to your online accounts. When you use 2FA, you need to enter both your password and a code from an authenticator app to log in. Authenticator apps generate codes using a time-based one-time password (TOTP) algorithm. This means that the code changes every few seconds, so it is very difficult for someone to guess or intercept. To set up an authenticator app, you will need to download an app from the app store on your phone or tablet. Once you have downloaded the app, you will need to scan a QR code or enter a code from the service you want to use 2FA with. Two examples of TOTP authentication apps are * Google Authenticator * Microsoft Authenticator * Authy * Bitwarden The app will then generate a six-digit code every few seconds. When you log in to the service, you will need to enter this code along with your password. Using an authenticator app is a great way to protect your online accounts. It is more secure than using 2FA with text messages, because the identity of the mobile phone on the cellular network can be stolen or spoofed so that your private messages are routed to the baddies. ### **Here's some basic information on TOTP:** * TOTP is a cryptographic algorithm that generates one-time passwords (OTPs) that are valid for a short period of time. * OTPs generated by TOTP are typically 6 digits long and can be used to authenticate users to online services. * TOTP is a secure method of authentication because it is difficult to guess or intercept OTPs. * Authenticator apps that use TOTP are a convenient way to generate and use OTPs. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.zipwire.io/fundamentals/security/authenticator-mobile-apps.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.