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

Abstract

Most contemporary file synchronization systems rely
on centralized cloud infrastructure, which raises concerns regarding
data privacy, service availability, dependence on external
infrastructure, and user control over personal data. As users
increasingly operate across multiple devices, providing secure
cross-platform synchronization without persistent centralized
storage remains a significant challenge. This paper presents
PocketBridge, a privacy-focused cross-platform peer-to-peer communication
and file synchronization framework that enables communication
and synchronization between authenticated personal
devices. The proposed framework adopts a layered architecture
that separates connection coordination from application data
transfer. WebSocket is used for device discovery, temporary
pairing, and signaling, while WebRTC DataChannels are used
for peer-to-peer data transfer. Temporary pairing credentials
and cryptographic device identities provide controlled device
authorization, while application-level encryption protects synchronization
content when supporting infrastructure is involved.
The framework operates within a web browser, enabling synchronization
across heterogeneous desktop and mobile platforms
without requiring separate platform-specific applications. The
implementation was evaluated through integrity and security
tests, cryptographic processing benchmarks, end-to-end filetransfer
experiments, synchronization reliability measurements,
and cross-platform browser compatibility tests. The results
demonstrate the feasibility of combining browser-based peerto-
peer communication, temporary device authorization, and
application-level protection for privacy-focused cross-platform
synchronization.