Proton Authenticator

Proton Authenticator is an open-source TOTP app from Proton, the company behind Proton Mail and Proton Pass. Scan a service’s QR code or enter its secret manually, and the app generates the rotating login code on the phone. Codes do not need a network connection, and the vault can be protected with the device’s fingerprint or other biometric lock.

Local use, backup and sync

An account is optional. Without one, entries stay in the local app and can be exported. The separate automatic backup option is also local: it is off by default, writes JSON files into a folder you choose, needs no account and is scheduled with no network requirement. It keeps the five newest automatic backups. If you set a backup password, the export is password-protected; without one, the JSON contains the secrets in plaintext, so choose a private folder and protect or encrypt any copy you move elsewhere.

A Proton account is for end-to-end encrypted synchronization across devices. That changes the network boundary: encrypted vault and account operations use Proton’s service, even though TOTP calculation and local folder backups do not.

The app supports importing existing codes, organising entries, searching them and copying either the current or upcoming code. QR scanning uses the camera only when you choose it. Before moving a live two-factor account, save the website’s recovery codes and verify a generated code at the website; never rely on an untested export as the only copy of the secret.

The F-Droid privacy difference

This package is the project’s F-Droid flavour. In its source, the F-Droid implementation forces usage telemetry off and removes the setting; its Sentry initializer is a no-op and the APK contains no Sentry SDK. Our scan also found no recognised tracker SDKs.

It is not network-free. The common startup code starts Proton’s feature-flag refresh service, and account sign-in and encrypted sync reach Proton. F-Droid marks NonFreeNet because the app contacts a proprietary backend to decide whether progressively rolled-out experimental features are enabled. It separately marks Tracking with the repository warning that users can be fingerprinted even when they do not use online features.

There is also a distinct third-party request path. The app maps recognised issuer names to remote logo URLs and Coil downloads them for entry cards, caching the result on disk. Most mappings use Google’s favicon service and others use DuckDuckGo or Clearbit. A request can disclose the user’s IP address and, through the requested service domain, which issuer has a two-factor entry on that device—even when the user has not signed in to Proton. The interface has no switch to disable these logo downloads; an unmapped issuer falls back to a generated letter icon.

Version 1.3.9

The 1.3.9 release notes contain core-library and translation updates rather than a new user feature. This page therefore describes capabilities present in the measured build without attributing all of them to that update.

About this file

• This is F-Droid’s build of Proton Authenticator 1.3.9, compiled from source and signed with F-Droid’s key. Because its package name and signer differ from the Play build, Android keeps the two installations separate.
• The 93.5 MB APK runs on Android 8.1 or later and contains native libraries for 64-bit ARM, 32-bit ARM and x86_64. It declares ten permissions for network state, internet, the optional camera, biometrics, notifications, boot, a foreground service and wake lock.
• Our scan found no tracker SDKs; the F-Droid anti-feature disclosures and the remote issuer-logo requests above still apply.
• The source is licensed under GPL-3.0-or-later. We retain only the F-Droid listing’s automatic-backup settings screenshot; the other listing images prominently reproduce third-party service or competing-app logos.

Flagged by F-Droid:

• NonFreeNet: Relies on or promotes a proprietary network service.
• Tracking: IzzyOnDroid flags this app for tracking or reporting user activity.

CPU types in this build: arm64-v8a (64-bit ARM, almost every phone since 2017); armeabi-v7a (32-bit ARM, older and budget phones); x86_64 (64-bit Intel, emulators and Chromebooks).

Versions currently kept in the F-Droid repository. We host and check only the newest one. Full changelog.