The Google Authenticator project includes implementations of one-time passcode generators for Android. One-time passcodes are generated using open standards developed by theInitiative for Open Authentication (OATH) (which is unrelated toOAuth).

This implementation support the HMAC-Based One-time Password (HOTP) algorithm specified inRFC 4226 and the Time-based One-time Password (TOTP) algorithm specified inRFC 6238.

TheAndroid mobile app supports:

• Multiple accounts
• Support for 30-second TOTP codes
• Support for counter-based HOTP codes
• Key provisioning via scanning a QR code
• Manual key entry ofRFC 3548 base32 key strings

DISCLAIMER: This open source project allows you to download the code that powered version 2.21 of the application. Subsequent versions contain Google-specific workflows that are not part of the project.