2FAS vs Proton Authenticator Comparison

2FAS keeps the secrets on your phone and has no copy of them. On Android the app's database is encrypted with a random key protected by the phone's keystore. On iPhone, according to the app's public source code, its own encryption of stored secrets uses a key built into the app, so the protection there comes from the phone itself and its passcode. If you turn on the Android Google Drive backup without a backup password, Google stores a readable copy. A PIN or biometric lock for the app is optional.

Without sync, the secrets stay on the device, encrypted with a random key kept in the system key store (Android Keystore, Apple Keychain, Windows Credential Manager or a Linux Secret Service). With sync, Proton stores an encrypted copy; by Proton's account, only your Proton account key can open it. That is Proton's statement: no independent audit of the app has been published.

Not encrypted on Android unless you set a backup password; encrypted on iPhone. The backup is off until you turn it on; the Android app reminds you on its home screen. On Android the copy goes to a hidden folder of your Google Drive and Google can read it if you set no password. On iPhone the copy goes to iCloud, encrypted by the app with a random key kept in your iCloud Keychain, or with a key made from your own password if you set one.

Sync to a Proton account is off until you sign in. Automatic backup files to a folder you choose are also off by default on Android; the iPhone app offers them during setup. Backup and export files can be protected with a password of your own. On Apple devices, iCloud sync is a separate switch, off by default.

2FAS has no accounts of its own. The optional cloud backup uses your Google account on Android and your Apple account on iPhone.

A Proton account is needed only for sync between devices. Google Play's data-safety section lists an email address as the only data collected.

The app is published by Two Factor Authentication Service, Inc., which gives an address in Henderson, Nevada. Its licence agreement for the app is governed by the laws of Delaware, with disputes going to Delaware courts or arbitration.

Published by Proton AG, Route de la Galaise 32, 1228 Plan-les-Ouates, Geneva. Proton's privacy policy says it discloses the limited user data it holds only when legally obliged, on a binding request from the competent Swiss authorities.

2FAS says the company was founded in 2015 and its team works fully remotely. It also makes 2FAS Pass, a password manager with a paid plan.

Proton AG's primary shareholder is the Proton Foundation, a Swiss non-profit registered in Geneva; Proton says no change of control can happen without the Foundation's consent.

2FAS Auth is free and has no ads. The company takes donations through PayPal and says they go to app development; it also sells a yearly plan of its separate password manager.

The app has no paid tier and no ads and brings in no revenue of its own; Proton AG develops it alongside its other services.