FreeOTP – open source two-factor authenticator

FreeOTP is a two-factor authentication application for Android that generates one-time passwords used to protect online accounts. It is designed for services that implement standard one-time password protocols and does not require a proprietary server-side component.

The app supports HOTP, the HMAC-Based One-Time Password Algorithm defined by RFC 4226, and TOTP, the Time-Based One-Time Password Algorithm defined by RFC 6238. Authentication tokens can be added by scanning a QR code or through manual configuration.

FreeOTP provides considerable flexibility in its token configuration. Besides the shared secret, tokens can specify the hashing algorithm, number of digits, validity period and other parameters. Supported hashing algorithms include SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512. Individual tokens can also be configured to require recent device authentication before their secret can be accessed.

Backup and restore functionality helps when moving to another device or protecting against data loss. FreeOTP encrypts token data using a master key stored in the Android Keystore. It supports Android’s automatic Google Account backup mechanism as well as manual encrypted backups to external storage. Restoring a backup requires the master password.

This is free and open source software.

Key Features

• Generates HOTP one-time passwords conforming to RFC 4226.
• Generates TOTP one-time passwords conforming to RFC 6238.
• Adds authentication tokens by scanning QR codes.
• Supports manual token configuration.
• Supports SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512 hashing algorithms.
• Supports configurable token periods and code lengths.
• Provides encrypted backup and restore functionality.
• Stores encryption keys using the Android Keystore.
• Supports Android automatic backup and manual external backups.
• Can require device authentication before accessing a token secret.
• Supports inverted QR codes.
• Can sort tokens by most recently used.
• Offers a graphical Android interface.

Website: github.com/freeotp/freeotp-android
Support:
Developer: FreeOTP project
License: Apache License 2.0

FreeOTP is written in Java. Learn Java with our recommended free books and free tutorials.

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