Real-Time Chat Application with E2EE systems are considered most secured methods of communication online. However recent studies from 2025-26 shows some security failures in post-quantum era due to incomplete migration from classical cryptography, lack of infrastructure transparency, and absence of time-aware security mechanisms. Another issue is the lack of cryptographic binding between ratchet state and infrastructure transparency under post-quantum threat models. Current platforms such as WhatsApp, signal and MLS based protocols maintains forward secrecy. However, they depend on classical cryptography but do not verify cryptographic evolution with system-level trust state. In this paper, we present Trust-Mesh, a Post-Quantum Verifiable Time-Ratcheted Messaging Protocol (PQ-VTRM) for real-time communication. This protocol combines post quantum key encapsulation, Time-indexed forward ratcheting, Verifiable transparency, Post quantum time-lock message capsules, secure group rekeying, Automatic key verification and trust indicators. Our proposed system covers a clear gap by combining postquantum migration, verifiable infrastructure transparency, time-selective encryption, and usable group trust management into a single deployable messaging architecture.
Real-Time Chat Application with E2EE systems are considered most secured methods of communication online. However recent studies from 2025-26 shows some security failures in post-quantum era due to incomplete migration from classical cryptography, lack of infrastructure transparency, and absence of time-aware security mechanisms. Another issue is the lack of cryptographic binding between ratchet state and infrastructure transparency under post-quantum threat models. Current platforms such as WhatsApp, signal and MLS based protocols maintains forward secrecy. However, they depend on classical cryptography but do not verify cryptographic evolution with system-level trust state. In this paper, we present Trust-Mesh, a Post-Quantum Verifiable Time-Ratcheted Messaging Protocol (PQ-VTRM) for real-time communication. This protocol combines post quantum key encapsulation, Time-indexed forward ratcheting, Verifiable transparency, Post quantum time-lock message capsules, secure group rekeying, Automatic key verification and trust indicators. Our proposed system covers a clear gap by combining postquantum migration, verifiable infrastructure transparency, time-selective encryption, and usable group trust management into a single deployable messaging architecture.
Quantum computing is a potentially significant threat to classical cryptographic methods, commonly influenced for mobile communication security. In this paper, we propose one secure channel for private, personal mobile devices that are based not only on post-quantum cryptographically algorithm but also to secure communications in the quantum era. NIST-spec kemsKyber2 and Saber represent for irreplaceable session keys in communication against prospective quantum threats. The keys are periodically replaced in order to provide forward secrecy and to protect against an eventual compromise. In addition to the features of mobile platforms, the scheme employs a lightweight authentication protocol applied to lattice-based cryptography which has been shown to be secure and low resource overhead. Testing the proposed solution was practicable and wielded manageable results since it was performed on Android devices with an average key exchange latency of less than 250 milliseconds and a secure message delivery of below 500 milliseconds without compromising the AES-256 equivalence level of privacy. The engineers and software developers with the results from this study could safely claim that practically, it is indeed doable to transfer secure messages on mobile platforms in the post-quantum era and they’d have that same level of confidence with respect to the adoption of cipher suites based on post-quantum standards within any future communication systems.Keywords: Post-quantum cryptography, quantum-resistant encryption, key encapsulation mechanism (KEM), end-to-end encryption (E2EE), quantum key distribution (QKD), mobile communication security, lattice-based cryptography, publickey infrastructure (PKI), quantum computing threats.
Because of Shor’s method, it is expected that quantum computers will have the capability to decipher current public key encryption methods. Consequently, there is a need to replace existing public key cryptography with quantum-resistant cryptography, also known as post-quantum cryptography (PQC) algorithms. In the last twenty years, significant progress has been made in the field of PQC research, leading to the creation of various algorithms that are proven to be resistant to quantum attacks. Several organizations responsible for standardization have already selected and are in the process of standardizing specific PQC algorithms.In popular instant messaging and voice-over IP applications like Signal, Facebook Messenger, and WhatsApp, the Signal Protocol provides end-to-end encryption (E2EE) and additional security features such as forward secrecy, future secrecy, authentication, asynchronous communication, and deniability. The protocol utilizes the ECDH Curve25519 key exchange and hash-based key derivation algorithms to accomplish this. However, the ECDH key exchange is vulnerable to attacks from quantum computers, which can compromise the security of contemporary cryptographic techniques by obtaining the corresponding public keys. Therefore, there is a need to replace the ECDH key exchange with a quantum-safe key exchange scheme that is resistant to attacks from quantum computers.In this context, the focus is on investigating post-quantum cryptography (PQC) that can provide robust security against quantum computing threats and proposing an end-to-end encryption scheme.
Modern instant messaging systems require end-to-end (E2E) security guarantees while operating over server-mediated infrastructures that cannot be fully trusted. At the same time, the impending transition to post-quantum cryptography raises nontrivial challenges for the design of secure messaging protocols that preserve these guarantees. In this work, we present the design of a post-quantum end-to-end secure protocol for instant messaging applications under an untrusted relay model. The proposed construction relies on lattice-based primitives standardized by NIST, namely ML-KEM for key establishment and ML-DSA for authentication, and follows a Double-KEM pattern combined with explicit context binding to derive an E2E session key known only to the communicating clients. The server acts solely as an authenticated relay and never gains access to plaintext messages or session keys. In addition to the protocol design, we complement the protocol description with an automated symbolic verification using ProVerif, establishing injective mutual authentication and session-key secrecy under a Dolev–Yao adversary model. Finally, we characterize the computational cost of different authentication and verification policies and evaluate the performance of the handshake on heterogeneous cloud-based architectures. The results provide practical insight into the feasibility of deploying post-quantum end-to-end secure protocols within existing instant messaging infrastructures.
Quantum computing poses a serious threat to traditional cryptography, with algorithms like RSA and ECC being vulnerable to attacks such as Shor’s algorithm. To address this, we propose a Post-Quantum Secure Chat Application using lattice-based cryptography, specifically CRYSTALS-Kyber for key exchange and CRYSTALS-Dilithium for digital signatures. The system provides end-to-end encryption with forward secrecy, ensuring message confidentiality, authenticity, and integrity. Mathematical formulations of key encapsulation, encryption, and signature verification are presented, alongside performance benchmarks. Experimental results show that the application achieves practical latency and throughput on real devices while resisting quantum attacks. This work demonstrates that integrating post-quantum algorithms into messaging platforms is both feasible and essential for secure future communication.
Abstract— The advancement of quantum computing presents significant risks to conventional cryptographic systems that secure modern communication networks. This paper proposes an Adaptive Quantum–Classical Trust Communication System (AQCTCS), a hybrid secure messaging framework designed to enhance resilience against both classical and quantum threats. The system integrates three security layers: AES-256 for classical encryption, Post-Quantum Cryptography (PQC) for quantum-resistant protection, and a BB84-based Quantum Key Distribution (QKD) simulation for high-risk scenarios. A Trust Engine continuously evaluates security indicators, including anomaly detection parameters and Quantum Bit Error Rate (QBER), to compute a dynamic trust score. Based on this score, an Adaptive Security Controller automatically selects the appropriate encryption mode, balancing performance and security. The platform is implemented as a web application using React for the frontend, FastAPI for backend services, and Qiskit for QKD simulation. AQCTCS demonstrates an adaptive, scalable, and future-ready communication architecture suitable for post-quantum environments. Keywords— Quantum Key Distribution, Post-Quantum Cryptography, AES-256, Trust Engine, BB84 Protocol, Adaptive Encryption, Secure Messaging, QBER.
The advent of cryptographically relevant quantum computers poses an existential threat to current public-key cryptographic systems (RSA, ECC) widely used in digital communication protocols such as TLS, IPsec, VPNs, and secure messaging. Traditional systems face risks from "Harvest Now, Decrypt Later" attacks, compromising long-term confidentiality of sensitive data in finance, healthcare, government, and critical infrastructure. This paper proposes Quantum Shield, a comprehensive post-quantum secure framework for next-generation digital communication. It integrates NIST-standardized post-quantum algorithms (ML-KEM for key encapsulation, ML-DSA and SLH-DSA for digital signatures) with hybrid crypto-agile designs, hardware acceleration support, and role-based access controls. The system ensures quantum-resistant key establishment, authentication, and end-to-end encryption while maintaining low latency and high throughput. Experimental evaluation on simulated network traffic demonstrates acceptable performance overhead, enhanced resistance to quantum attacks, improved traceability, and secure multi-party coordination. Quantum Shield bridges the gap between classical and quantum-safe infrastructures, fostering trust and compliance in an era of quantum threats.