🛡️ Zero-Knowledge & Local-First Architecture

Privacy Policy for ScanZen

Effective Date: October 19, 2026 | Application: ScanZen Document Scanner & PDF Utility | Package: com.Kalpesh.scanzen

🔒 Privacy Summary

ScanZen is built with a privacy-first, zero-knowledge architecture. Document scanning, camera edge detection, Optical Character Recognition (OCR), inpainting, and PDF manipulation take place 100% locally on your device. ScanZen does not operate private servers, does not log user activities, does not sell data, and does not upload your documents anywhere unless you explicitly initiate a cloud backup.

1. Overview and Core Principles

This Privacy Policy explains how ScanZen ("we", "our", or "the app") treats information when you use our mobile application published on Google Play.

We believe that your personal, legal, tax, medical, and financial documents belong exclusively to you. Our engineering is specifically designed to eliminate third-party telemetry, remote tracking, and unwanted cloud storage dependencies.

2. Data Collection & Processing Practices

ScanZen does not collect, harvest, or transmit personally identifiable information (PII) to our developers or external analytics platforms.

Scanned Images & Documents: Photos captured via the camera or chosen from your photo gallery remain strictly in local app storage on your device.
Optical Character Recognition (OCR): Text recognition operates using on-device Google ML Kit models or platform native APIs. No text or image bytes are sent over the network for OCR processing.
Safe Vault Files: Documents designated for the Safe Vault are encrypted using 256-bit AES encryption at rest and isolated behind a secondary user-chosen PIN.
Analytics & Telemetry: We do not embed third-party advertising SDKs, tracking pixels, or behavioral analytics frameworks.

3. Device Permissions & Why They Are Needed

ScanZen only requests Android permissions strictly required to perform document scanner and PDF utility operations. Each permission and its explicit purpose is outlined below:

Permission	Type	Explicit Purpose in ScanZen
android.permission.CAMERA	Dangerous	Allows taking photos of documents, receipts, and ID cards via Google Play Services ML Kit Document Scanner.
android.permission.USE_BIOMETRIC	Normal	Enables local fingerprint or facial unlock via Android's secure BiometricPrompt API. Raw biometric data is never accessible to the app.
android.permission.INTERNET	Normal	Used strictly when the user manually initiates cloud synchronization (Google Drive, Microsoft OneDrive, Dropbox, or WebDAV/Nextcloud).
android.permission.ACCESS_NETWORK_STATE	Normal	Checks network availability to honor the user's "Wi-Fi Only Sync" data saver setting.
android.permission.VIBRATE	Normal	Provides subtle haptic feedback when capturing scans, unlocking the Safe Vault, or completing PDF operations.

4. Biometric Authentication Security

When you activate Fingerprint or Face Unlock, authentication is managed entirely by Android's hardware-backed Trusted Execution Environment (TEE) / Keystore via AndroidX.Biometric.

ScanZen receives only a binary verification result (Success or Failure). ScanZen never reads, stores, or transmits your fingerprint or facial biometric templates.

5. Optional Third-Party Cloud Services

ScanZen provides optional integrations for users who desire remote document backups:

Google Drive, Microsoft OneDrive, Dropbox: Authentication is handled directly via official OAuth 2.0 PKCE consent screens. ScanZen stores access tokens in Android's encrypted SecureStorage.
WebDAV / Nextcloud / Personal NAS: Credentials entered for private WebDAV servers communicate solely with the specific host endpoint designated by the user.
Cellular Data Protection: If enabled, the "Wi-Fi Only Sync" switch prevents any file upload from taking place over cellular data.

6. Data Retention and Deletion Rights

Because all document databases, cached files, and configuration keys reside exclusively on your physical device:

Permanent Document Deletion: Deleting a document within ScanZen immediately removes it from storage, or moves it to the local 30-day Trash bin where it is auto-purged.
Full App Reset / Uninstallation: Uninstalling ScanZen or clearing its app data in Android Settings instantly and irrevocably wipes all scanned files, vault documents, and saved settings from the device.

7. Children's Privacy (COPPA Compliance)

ScanZen does not knowingly collect or solicit personal information from children under the age of 13 (or under 16 in the European Union). The app does not display targeted advertising, behavioral profiling, or external community chat features.

8. Changes to This Privacy Policy

We may update our Privacy Policy periodically to reflect app updates or regulatory compliance requirements. Any revisions will be published on this page with an updated "Effective Date" at the top of the policy.

9. Contact Information

If you have questions, inquiries, or feedback regarding ScanZen's privacy practices, you can reach out directly via:

Developer: Kalpesh
Support Email: kalpesh@kalpesh.dev