The Architecture of a Secure P2P File Transfer System
Deep dive into how xtransfiles uses Rust, Tokio, and X25519 to deliver secure, high-performance file transfers.
Introduction
In an era where cloud storage has become the default for file sharing, privacy and speed often take a back seat. We built xtransfiles to challenge this status quo.
xtransfiles is a cross-platform, P2P file transfer tool written in Rust. It allows you to transfer files directly between devices without any intermediate server, ensuring maximum privacy and LAN-speed performance.
The Problem with Cloud Transfer
- Privacy: Your files live on someone else’s computer.
- Speed: Uploading to the cloud and then downloading is twice the bandwidth usage.
- Limits: File size limits and storage quotas.
xtransfiles solves this by creating a direct, encrypted tunnel between devices.
Core Technology
1. Rust & Tokio
We chose Rust for its memory safety and performance. The core daemon is built on top of Tokio, an asynchronous runtime that allows us to handle thousands of concurrent connections with minimal resource usage.
2. X25519 & ChaCha20-Poly1305
Security is not an afterthought. Every transfer is authenticated and encrypted:
- Key Exchange: X25519 (Elliptic Curve Diffie-Hellman)
- Encryption: ChaCha20-Poly1305 (Authenticated Encryption)
3. Local Discovery
To avoid manual IP entry, xtransfiles broadcasts presence packets on UDP port 49872. When a peer receives this packet, it can initiate a TCP connection to the sender’s advertised port.
Conclusion
By leveraging modern cryptography and systems programming, xtransfiles provides a tool that is both simple to use and mathematically secure.