Terms of Service

2. About Sino Privacy Vault

Sino Privacy Vault is a local-first encrypted backup and synchronization application.

• Sino encrypts your selected files on your device before storing them in your chosen cloud storage provider
• Files you place in the Local Vault are stored encrypted on your device, and are copied to your cloud storage only for folders you choose to back up
• Sino is software only
• Sino is not a cloud storage provider and does not host user backups

3. Eligibility

You represent that you:

• Are legally permitted to use the App
• Comply with applicable laws
• Have authority to use any cloud storage account connected to Sino

4. User Responsibilities

You are responsible for:

• Choosing a strong password or recovery method
• Protecting your device
• Safeguarding your recovery keys
• Maintaining access to your cloud storage account
• Ensuring your backups are current
• Choosing which Local Vault folders to back up to your cloud storage

You are solely responsible for the files you choose to encrypt, upload, restore, or delete.

5. Encryption and Security

Sino is designed to encrypt files before they leave your device.

You acknowledge that:

• Encryption keys remain under your control
• Sino cannot recover your encryption keys
• Sino cannot decrypt your backups
• Sino cannot access your plaintext files
• Integrity Protection (Version 2): Sino's security and metadata artifacts are authenticated with AES-256-GCM, so altered files are rejected, and carry a SHA-256 checksum so that storage corruption is recognised and reported.
• Shadow Mirroring: To provide off-grid resilience, Sino silently maintains a physical local mirror of your latest Vault Snapshot and Public Salt. This ensures you can reconstruct your library index even if your cloud provider is unreachable.
• Random Access Cryptography: Sino uses Chunked GCM to enable secure, high-performance streaming and seeking of media files. This ensures that only the specific parts of a file you are viewing are decrypted in RAM at any given time.
• Forensic Restoration Policy: If you utilize the "SECURE" restoration mode, your restored files are stored encrypted in Sino's private storage. You acknowledge that triggering a Panic event (the Terminus Protocol) will permanently erase local application data and keys, including Local Vault files kept only on that device. Panic events do not delete your cloud backups; deleting them is the separate Wipe Cloud action.
• Device Revocation: If you revoke a device, it erases its local Sino data the next time it connects. Revocation cannot undo access to files that device had already decrypted, and it depends on that device connecting again.

Loss of your recovery information will permanently prevent access to encrypted backups, as Sino does not store, possess, or have any means to recover your keys.

6. Cloud Storage Providers

Sino supports third-party cloud storage services.

When using these services:

• You remain subject to their terms and policies
• Storage availability is outside Sino's control
• Storage quotas are determined by your provider
• Outages or service interruptions are the responsibility of the provider

Sino is not responsible for the availability, performance, security, or continued operation of third-party cloud services.

7. Universal OS Integration (Virtual Drive)

Sino provides a Virtual Drive feature using native operating system mechanisms (SAF on Android, Dokany on Windows).

You acknowledge that:

• Files are read-only through the Virtual Drive, except in Local Vault folders, where other applications can also create, change, rename, move and delete files and folders. Changes made there by other applications are saved into your vault and, for backed-up folders, to your cloud storage.
• On Windows, the Virtual Drive mounts to the first free drive letter starting from S:.
• Enabling the Virtual Drive allows other authorized applications on your device to see and request your decrypted files on-demand.
• Decryption for the Virtual Drive happens in volatile RAM only via "Reliable Pipes." Files written into Local Vault folders are held encrypted until they are saved. No plaintext data is written to your physical storage.
• The Virtual Drive respects your vault's lock status: it shows no files (on Windows, it is unmounted) while the vault is locked, and requires biometric or password authentication to unlock.

8. Ownership of Data

• You retain ownership of all files you encrypt using Sino Privacy Vault
• Nothing in these Terms transfers ownership of your content to Sino
• Because Sino is designed around end-to-end encryption, Sino generally cannot access or inspect your stored files

9. Acceptable Use

You agree not to use Sino:

• To violate applicable laws
• To infringe intellectual property rights
• To distribute malware
• To interfere with cloud providers
• To abuse synchronization services
• To attempt unauthorized access to systems
• To bypass security mechanisms

You remain solely responsible for your use of the software.

10. Software Updates

Sino may release updates that:

• Improve security
• Add functionality
• Fix defects
• Improve compatibility

Some updates may be required for continued compatibility with cloud providers or newer operating system versions.

11. Open Source Software

Sino may incorporate third-party open source components.

• kmp-mega: Implementation provided by Anders Carlsen (github.com/acarlsen). Used under MIT License.
• Those components remain subject to their respective licenses
• Nothing in these Terms replaces or overrides applicable open source licenses

12. Intellectual Property

Except where otherwise noted, Sino Privacy Vault, its branding, documentation, source code, graphics, and associated materials remain the property of their respective owners.

These Terms grant you a limited, non-exclusive, revocable license to use the App in accordance with these Terms.

13. Pricing and Licensing

• Personal Use: Personal use means use by an individual for their own, non-commercial purposes.
• Windows: Sino for Windows is free for personal use.
• Android: Sino for Android requires a one-time purchase through Google Play. There is no recurring fee for personal use, and the purchase can be restored on any Android device signed in to the same Google account.
• Business Use: Any use by or on behalf of a business or other organisation, including companies, partnerships, non-profits, government bodies, and sole traders or freelancers using Sino for their work, requires an active business subscription.
• Business Tiers: Business subscriptions are offered in tiers based on the size of the organisation. Prices and tier limits are shown at the time of purchase.
• Business Coverage: A business subscription covers each person it licenses on both Windows and Android. No separate Android purchase is needed for business use.
• Renewal and Ending: A business subscription renews each billing period until it is cancelled. When it ends, business use of the App must stop. Your vault and files remain yours, and you can still open and export them.
• License Checks: The App may check a business license on your device. This check does not send your files, file names or keys to us.
• Transactions & Refunds: Purchases through Google Play or the Microsoft Store are subject to that store's billing and refund policies. Business subscriptions are subject to the terms shown at checkout.
• License Grant: Subject to these Terms, you receive a non-transferable, non-exclusive license to use the App: for personal use, on devices you own or control; for business use, for the people your subscription covers.

14. No Warranty

The App is provided on an "AS IS" and "AS AVAILABLE" basis.

To the fullest extent permitted by applicable law, Sino makes no warranties regarding:

• Uninterrupted availability
• Compatibility with every device
• Uninterrupted cloud services
• Prevention of all data loss
• Suitability for a particular purpose

While Sino is designed with security as a primary objective, no software can guarantee complete protection against every threat or circumstance.

15. Limitation of Liability

To the maximum extent permitted by law, Sino and its contributors shall not be liable for:

• Loss of encrypted data
• Forgotten passwords or recovery keys
• Deleted cloud backups
• Cloud provider failures
• Device failures
• Indirect, incidental, consequential, or special damages
• Loss of profits
• Business interruption
• Loss of goodwill

You acknowledge that encrypted backups cannot generally be recovered without the appropriate recovery credentials.

16. Backup Responsibility

Sino is a backup tool, not a guarantee against data loss.

You are responsible for:

• Verifying backups
• Maintaining multiple copies of important data where appropriate
• Periodically testing restoration procedures
• Backing up Local Vault folders you cannot afford to lose: files kept only on a device are lost if that device is lost, damaged or reset, or (on Android) if Sino is uninstalled

17. Suspension or Termination

• Your right to use Sino automatically terminates if you violate these Terms
• You may stop using Sino at any time by uninstalling the application. Uninstalling deletes data kept only on that device, including Local Vault files that are not backed up
• Termination does not automatically remove encrypted backups from your cloud storage account

18. Privacy

Your use of Sino is also governed by the Sino Privacy Policy.

The Privacy Policy explains what information Sino processes and how your information is protected.

19. Export Compliance

Cryptographic software may be subject to export control laws in certain jurisdictions.

You are responsible for complying with all applicable import, export, and sanctions laws governing your use of Sino.

20. Changes to These Terms

• These Terms may be updated periodically
• Material changes will be reflected by updating the Effective Date
• Continued use of Sino after revised Terms become effective constitutes acceptance of the updated Terms

21. Governing Law

These Terms shall be governed by and interpreted in accordance with the laws of the State of Victoria, Australia, without regard to conflict of law principles. Any dispute arising under these Terms shall be subject to the non-exclusive jurisdiction of the courts of Victoria, Australia, unless otherwise required by applicable consumer protection laws in your local jurisdiction.

22. Contact

If you have questions regarding these Terms, please contact us at:

23. Acknowledgement

By using Sino, you acknowledge that:

• You understand how the encrypted backups operate
• You are responsible for protecting your recovery credentials
• You understand that Sino cannot recover encryption keys or decrypt your backups on your behalf
• You accept these Terms of Service