2FAS Auth – private two-factor authenticator for Android

2FAS Auth is a free and open source two-factor authentication application for Android. It generates the time-based and counter-based one-time passwords used by thousands of online services to provide an additional layer of authentication beyond a conventional password.

The app takes a local-first approach. Authentication secrets are kept on the user’s device and 2FAS does not require an account. It works offline, so generating a token does not depend on an internet connection or on the availability of the developer’s infrastructure.

Users who want additional protection against losing their phone can enable encrypted synchronization with their own Google Drive account. 2FAS also supports manual import and export using its backup format, including password-protected exports. Tokens can be imported from several other authenticator applications, making migration from an existing setup considerably less laborious.

The interface offers tools for managing larger token collections, including search and token customization with groups, icons, badges and labels. Access to the application can be protected with a PIN, while tokens can be hidden until they are needed.

2FAS Auth also integrates with the project’s optional browser extension. After pairing a browser with the mobile application, a login request can be confirmed on the phone and the required token passed to the browser over an end-to-end encrypted connection. This avoids manually finding and typing six-digit codes while leaving the user in control of the authorization.

This is free and open source software.

Key Features

• Supports TOTP and HOTP authentication standards.
• Works with services supporting standard one-time passwords.
• Stores authentication data locally on the Android device.
• Works offline and does not require a 2FAS account.
• Supports encrypted backup and synchronization using Google Drive.
• Imports and exports 2FAS backup files.
• Supports password-protected backup exports.
• Imports tokens from several competing authenticator applications.
• Adds tokens by scanning QR codes or importing QR code images.
• Provides search for quickly locating authentication tokens.
• Supports token organization and customization with groups, icons, badges and labels.
• Can protect access to the application with a PIN.
• Can conceal authentication tokens until the user chooses to display them.
• Integrates with the optional 2FAS browser extension.
• Uses end-to-end encryption for communication with its browser extension.
• Provides a trash facility for recovering accidentally deleted tokens.

Website: github.com/twofas/2fas-android
Support:
Developer: Two Factor Authentication Service, Inc.
License: GNU General Public License v3.0

2FAS Auth is written in Kotlin. Learn Kotlin with our recommended free books and free tutorials.

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