NullKey Create the backup
In NullKey, open the backup action and choose a destination in Android’s document picker. The chosen provider controls where that file is stored and may sync it under its own terms.
Check before relying on it
After saving, NullKey automatically rereads the archive, authenticates the index, encrypted item segments and thumbnails, and checks that it matches the vault snapshot. Wait for the message that says the backup was saved and checked; if the check fails, do not rely on that file.
Practise a safe restore
Keep the backup and its matching passphrase or recovery key separate. Restore into an empty test vault; restore does not overwrite an existing vault. Check sample contents before treating the process as familiar.
Remember older exports
A backup reflects the vault at export time. Later passphrase changes or recovery-key rotation do not update previous backup files. Keep the credential needed for each backup you retain.
