How to Use:
How to Set Up and Restore Your Encrypted Vault Backup
Your financial data lives on your device — which means backing it up is your responsibility. Here's how to create an AES-256 encrypted vault backup and restore it perfectly on any new device.
What You'll Learn
- How to create your first encrypted vault backup with a master password
- How to store it safely using Google Drive's private app data folder
- How the Smart Merge Engine handles duplicate transactions when restoring
What It Does
Fin OS's zero-knowledge architecture means your data never touches external servers — which gives you complete privacy. The trade-off is that backup and restore is your responsibility, not the app's. This guide shows you how to do it correctly so you never lose a rupee of financial history, even when switching phones.
Who This Guide Is For
Any Fin OS user who wants to protect their data against phone loss, damage, or replacement. Recommended to complete within the first week of setup.
Create Your First Vault Backup
Navigate to Settings → Backup & Restore → Create Backup. You'll be prompted to set a Master Password for the backup. Choose a strong password you'll remember — this is the only key that can decrypt your vault. Enter it twice to confirm. Tap 'Create Encrypted Backup.' The app generates a single encrypted file: finos_vault_backup.json. The encryption process runs entirely on-device using AES-256-GCM. The file cannot be opened or read without your master password.
Your master password is not stored anywhere in the app, on our servers, or in your Google account. If you forget it, the backup cannot be decrypted. Write it down and store it somewhere physically secure.
Save to Google Drive (Recommended)
After creating the backup, tap 'Save to Google Drive.' Fin OS requests access to a private app data folder in your Google Drive — this is a hidden folder only your app can see, separate from your personal Drive files. The backup uploads there automatically. For Pro users, this can be set to run automatically on a weekly schedule under Settings → Backup → Auto Backup.
The Google Drive app data scope means Fin OS cannot see or access any of your personal Drive files — only the finos_vault_backup.json file it created. Your photos, documents, and other files are completely separate.
Save a Local Copy (Optional but Recommended)
Also tap 'Save to Device Storage' to create a local copy of the backup file. Save it to your internal storage or an SD card. This gives you two copies: one in Google Drive and one local. For critical financial data, redundancy is always correct. You can also manually copy the file to a USB drive or send it to yourself via email as an additional measure.
The local copy and the Drive copy are both encrypted with your master password. Storing them in multiple locations does not create any security risk — the encryption makes them unreadable without the password.
Restore on a New Device
Install Fin OS on your new device. On first launch, instead of tapping 'Start Fresh,' tap 'Restore from Backup.' Select your restore source (Google Drive or local file). Sign in to Google if restoring from Drive. Select the backup file. Enter your master password when prompted. The decryption and restore process runs on-device and takes 10–60 seconds depending on the size of your data.
You must remember your master password to restore. There is no recovery mechanism by design — this is what 'zero-knowledge' means. The security guarantee requires that we cannot decrypt your data even if we wanted to.
Understand the Smart Merge Engine
If you've logged any transactions on the new device before restoring (or if you're restoring onto a device that already has some Fin OS data), the Smart Merge Engine activates. It compares every transaction in the backup against every transaction on the device and intelligently identifies duplicates by matching date, amount, account, and description. Duplicates are skipped. Unique transactions from both sources are preserved. You get a single, clean, deduplicated financial timeline.
After restore, review the first few screens of your transaction history to verify the merge completed correctly. If you see obvious duplicates, use the manual delete function to clean them up and report the pattern to support@finosapp.com so we can improve the matching algorithm.
Pro Tip
Set a calendar reminder to create and save a new backup on the 1st of every month — right after your salary day reconciliation. A monthly backup means you can never lose more than 30 days of data in a worst-case scenario. Given that it takes 90 seconds, this is the best insurance in the app.
The backup cannot be decrypted without the master password. This is by design — it's the same guarantee that protects your data from anyone else. There is no password recovery option. Store your master password in a physically secure place: a written note in a safe, or a trusted password manager. If you lose it, your most recent on-device data is still accessible — you just cannot restore from the encrypted backup file.
Yes. Go to Settings → Backup → Change Master Password. You'll enter your current password, then set a new one. The app re-encrypts all existing backup files with the new password. Any old backup files on Drive or local storage will also need to be re-exported with the new password if you want them to be restorable.
The backup in Google Drive is encrypted with your master password before it leaves your device. Even if Google's systems were compromised, the encrypted file is unreadable without your password. Fin OS never sees or stores your master password. Your Google account protects the file from unauthorized access; your master password protects the content.
Ready to try it?
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