Security
The short version
MomentBackup runs on your computer and backs up to storage you control. When encryption is on, your files are encrypted on your machine before they leave it, with keys only you hold. There is no MomentBackup server in the path between your computer and your backup destination — we never receive or can read your data.
Encryption
- Strong, standard algorithms. Encrypted backups use XChaCha20-Poly1305 authenticated encryption, with keys derived from your passphrase using Argon2id. These are published, unmodified, widely-reviewed algorithms — no homemade cryptography.
- Your keys stay on your machine. The encryption key is generated locally and never transmitted. Your passphrase is never sent anywhere. The OS keychain can cache the key locally for unattended backups; it never leaves the device.
- A recovery key you control. Setup gives you a printable recovery key as a second way in. If you lose both your passphrase and your recovery key, your backups cannot be decrypted — by anyone, including us. That is the point.
No servers in your data path
MomentBackup is bring-your-own-destination: your backups go to your own disk, your NAS/SMB share, or your own cloud bucket or drive. We host no storage and keep no copy of your data. Your relationship with any third-party storage provider is directly with them.
Works offline and air-gapped
The app needs no account and sends no telemetry unless you opt in (off by default). License activation is verified offline against a key embedded in the app, so a machine that never touches the internet can be licensed by typing the key or carrying a license file on a USB stick. Restoring your existing backups is never gated behind a license check.
Integrity you can verify
Backups are content-addressed and checksummed (BLAKE3), so corruption is detectable. MomentBackup can verify a backup and repair recoverable damage, and a safe restore drill lets you confirm a real restore works before you ever depend on it. Where your cloud provider supports Object Lock / WORM retention, an off-site copy can be made immutable so it survives accidental or malicious deletion.
Reporting a vulnerability
Found a security issue? Please email [email protected] with the details. We take backup-tool security seriously and will respond.