A Privacy-Focused Cross-Platform Peer-to-Peer Communication and Synchronization Framework Using WebRTC and WebSocket

Abstract

Most contemporary file synchronization systems relyon centralized cloud infrastructure, which raises concerns regardingdata privacy, service availability, dependence on externalinfrastructure, and user control over personal data. As usersincreasingly operate across multiple devices, providing securecross-platform synchronization without persistent centralizedstorage remains a significant challenge. This paper presentsPocketBridge, a privacy-focused cross-platform peer-to-peer communicationand file synchronization framework that enables communicationand synchronization between authenticated personaldevices. The proposed framework adopts a layered architecturethat separates connection coordination from application datatransfer. WebSocket is used for device discovery, temporarypairing, and signaling, while WebRTC DataChannels are usedfor peer-to-peer data transfer. Temporary pairing credentialsand cryptographic device identities provide controlled deviceauthorization, while application-level encryption protects synchronizationcontent when supporting infrastructure is involved.The framework operates within a web browser, enabling synchronizationacross heterogeneous desktop and mobile platformswithout requiring separate platform-specific applications. Theimplementation was evaluated through integrity and securitytests, cryptographic processing benchmarks, end-to-end filetransferexperiments, synchronization reliability measurements,and cross-platform browser compatibility tests. The resultsdemonstrate the feasibility of combining browser-based peerto-peer communication, temporary device authorization, andapplication-level protection for privacy-focused cross-platformsynchronization.