Engineering behind the xPal private messaging app cross-device message deletion
4 hours ago
- xPal offers four distinct deletion features: Terminate (ends a single conversation and blocks the contact), Total Wipeout (deletes all data via reverse PIN), Remote Wipeout (for lost or stolen devices), and Flicker (disappearing messages with per-message timers).
- Cross-device deletion is a request, not a guarantee; once a message reaches another device, the app cannot force the recipient to delete it.
- xPal uses Replace And Destruct to overwrite encrypted data before deletion, making recovery difficult.
- Offline-Lock ensures that offline devices must process pending deletion requests before allowing access to chats.
- xPal does not store messages long-term on servers and avoids showing message content in push notifications.
- The system is designed to reduce stored data reliably under normal operation, but cannot control external recordings or screenshots.