A Novel Framework for End-to-End Encrypted Peer-to-Peer Communication
Avishek Golder, Sourov Kumar Nandi, Aishwarya Adhikary Eva, Aishwarya Roy, Md. Tabil Ahammed
Abstract
This paper presents the implementation and implementation of a secure, end-to-end encrypted peer-to-peer (P2P) chat system developed in Python. The system leverages modern cryptographic techniques, including Elliptic Curve Diffie-Hellman (ECDH) for key exchange and NaCl's Box construction (using XSalsa20 and Poly1305) for symmetric encryption, to ensure message confidentiality, integrity, and perfect forward secrecy. Unlike conventional chat applications, this system adopts a manual, out-of-band public key exchange method, eliminating the need for persistent key storage and reducing the attack surface. It operates in a fully decentralized manner with mDNS-based peer discovery, enabling seamless connection on local networks without centralized servers. The user interface, built with Tkinter, supports secure text and image communication, enriched with message bubbles, visual cues, and robust error handling. Designed for educational, disaster response, and privacy-centric scenarios, the system demonstrates a practical, serverless alternative to conventional messaging platforms while prioritizing security and user autonomy.