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P2P Chat

A fully decentralised, zero-registration messenger. There is no server, no account, and no email or phone number — a user's identity is a cryptographic key pair. Peers discover each other over a distributed hash table, connect directly (punching through NATs where needed), and exchange end-to-end encrypted messages.

Built as a Bachelor's thesis project for the Free University of Tbilisi (MACS).

Status: academic / proof-of-concept. Not security-audited for production use.

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Why it exists

Mainstream messengers tie your identity to a phone number and route every message through central infrastructure that can be logged, blocked, or compelled to hand over data. This project explores the opposite design point: no central authority anywhere in the system. Identity, discovery, connectivity, and encryption are all handled peer-to-peer.

Key features

• Keypair-as-identity — each user is an Ed25519 key pair. No registration, no personal data, nothing to leak. The public key is the address.
• Serverless peer discovery — peers are located through a Kademlia distributed hash table (and mDNS on the local network), so there is no directory server to take down or trust.
• Direct connectivity through NATs — transports over TCP, QUIC and WebRTC, with hole punching and relay fallback, so two peers behind home routers can still reach each other.
• End-to-end encryption — transport security via the Noise protocol / TLS; group messages encrypted with AES-256-GCM.
• Encrypted keys at rest — private keys are sealed with a key derived from the user's passphrase via Argon2id, so a stolen disk does not surrender the identity.

Tech stack

Layer	Technology
P2P networking	Go, libp2p — DHT Kademlia, Noise, multi-transport
Backend / daemon	Go
Frontend	React (JavaScript)
Cryptography	Ed25519, AES-256-GCM, Argon2id

Architecture

The project separates the peer-to-peer engine from the interface: a headless daemon owns all networking, discovery, and encryption, and a UI connects to it. Keeping the two apart means the networking layer can run and be tested on its own, without the frontend.

p2p-chat/
├── daemon/    # Go networking node — libp2p host, DHT peer discovery, transports, encryption
├── ui/        # React frontend
├── scripts/   # helper scripts for building and running the project
└── files/     # supporting project files