Quantum Secure Communication System

Quantum-Resistant Secure Communication System (QRSCS) About the Project The Quantum-Resistant Secure Communication System (QRSCS) is a secure messaging application designed to explore how post-quantum cryptography can help protect digital communication against future threats from quantum computing.

Traditional public-key cryptography may be vulnerable to sufficiently capable quantum computers. One related concern is “Harvest Now, Decrypt Later”: an attacker collects encrypted information today and attempts to decrypt it in the future. QRSCS is designed to address this emerging risk by integrating post-quantum cryptographic techniques into a practical communication workflow. Objectives

Integrate post-quantum cryptography into a messaging application.
Establish shared keys using ML-KEM-768.
Support digital signatures and identity verification using ML-DSA-65.
Encrypt messages and supported content using AES-256-GCM.
Support direct and group messaging, with encrypted file sharing.
Provide device authorization, management, and revocation features.
Demonstrate how quantum-resistant cryptographic components can be used in a real-world-style communication system. Key Technologies Technology Purpose ML-KEM-768 Post-quantum key encapsulation for establishing shared secrets ML-DSA-65 Post-quantum digital signatures AES-256-GCM Authenticated symmetric encryption for message and content protection Argon2id Password-based key derivation Python Core application and backend implementation Desktop and Web interfaces User access to messaging and account features PostgreSQL Persistent application data storage

Main Features

Direct messaging: Communicate privately with another user.
Group messaging: Exchange messages with authorized group members.
Encrypted file sharing: Send supported files and media through the messaging workflow.
Identity verification: Verify peer identities and detect changes in trust state.
Device management: Enroll, authorize, and revoke devices.
Cross-device support: Provide messaging workflows across desktop and web clients.
Security-focused design: Keep message content protected and use server-side relaying of ciphertext rather than relying on the server to read message plaintext. Security Approach QRSCS combines post-quantum key establishment and digital signatures with authenticated symmetric encryption. It also incorporates identity verification, device authorization, and key-management workflows.

The security of a complete messaging system depends on more than its algorithms. Implementation quality, private-key protection, endpoint security, correct authorization, nonce management, and thorough testing are also important. Therefore, QRSCS should be described as designed to provide quantum-resistant protection, not as absolutely quantum-proof. Intended Outcome The project aims to demonstrate a functional secure communication platform that brings post-quantum cryptography into everyday messaging features such as direct chats, group conversations, file sharing, and device management. Project Status Note This document describes the project's purpose, intended architecture, and major features. The availability and validation status of individual features may vary by client and test environment. In particular, desktop/web acceptance and physical Android validation should be reported separately, based on actual test evidence. Elevator Pitch QRSCS is a secure messaging platform designed to address future quantum-computing threats. It combines ML-KEM-768, ML-DSA-65, and AES-256-GCM to support protected messaging, file sharing, identity verification, and device management across desktop and web clients.