Post-quantum threshold cryptography requires complete elimination of classical assumptions to achieve genuine quantum resistance. This work presents a fully lattice-based dealerless distributed key generation (DKG) protocol with threshold CRYSTALS–Kyber implementation. We implemented a four-phase DKG protocol using lattice-based primitives: SIS-based commitments for verification, Ring-LWE secret sharing, and secure multi-party key derivation without reconstructing private keys. Our approach eliminates the need for a trusted dealer while maintaining 192-bit post-quantum security through exclusive reliance on lattice problems. Experimental evaluation demonstrates 𝒪(n2) communication complexity for lattice-based DKG setup across 3-20 participants, with secure threshold operations preserving key secrecy. Security analysis provides formal reductions to Ring-LWE and Ring-SIS assumptions, ensuring genuine quantum resistance throughout the protocol stack.
Post-quantum threshold cryptography requires complete elimination of classical assumptions to achieve genuine quantum resistance. This work presents a fully lattice-based dealerless distributed key generation (DKG) protocol with threshold CRYSTALS–Kyber implementation. We implemented a four-phase DKG protocol using lattice-based primitives: SIS-based commitments for verification, Ring-LWE secret sharing, and secure multi-party key derivation without reconstructing private keys. Our approach eliminates the need for a trusted dealer while maintaining 192-bit post-quantum security through exclusive reliance on lattice problems. Experimental evaluation demonstrates 𝒪(n2) communication complexity for lattice-based DKG setup across 3-20 participants, with secure threshold operations preserving key secrecy. Security analysis provides formal reductions to Ring-LWE and Ring-SIS assumptions, ensuring genuine quantum resistance throughout the protocol stack.
The advent of quantum computing threatens the cryptographic security of traditional blockchain systems, potentially rendering current encryption techniques obsolete. This paper explores quantum-resistant blockchain protocols that leverage post-quantum cryptographic algorithms to ensure secure transactions. We analyze various quantum-safe cryptographic methods, such as lattice-based, hash-based, and multivariate polynomial cryptography, evaluating their feasibility for blockchain applications. Through comparative analysis, we discuss their computational efficiency and security guarantees. Our findings suggest that integrating quantum-resistant cryptographic techniques into blockchain frameworks is essential for future-proofing decentralized systems. This paper explores the integration of quantum-resistant cryptographic algorithms within blockchain technology. The proposed approach utilizes CRYSTALS-Dilithium for digital signatures, ensuring secure transaction verification in a post-quantum era. While Kyber is a robust key exchange mechanism, it is not suitable for signing transactions. The implementation is tested on standard hardware, demonstrating feasibility without requiring specialized quantum computing infrastructure.
The advent of quantum computing poses a significant existential threat to the security foundations of current public-key cryptography, most notably the widely adopted RSA algorithm. Shor's algorithm, specifically, can efficiently break the mathematical problems underlying RSA and elliptic curve cryptography, necessitating a paradigm shift towards quantum-resistant solutions. This paper explores lattice-based cryptography as the leading candidate for this post-quantum era. We delve into the fundamental mathematical principles of lattices, including hard problems like the Shortest Vector Problem (SVP), Closest Vector Problem (CVP), Short Integer Solution (SIS), and Learning With Errors (LWE), which form the bedrock of their security. The paper reviews prominent lattice-based schemes such as NTRU, CRYSTALS-Kyber, CRYSTALS-Dilithium, and Falcon, highlighting their construction, security properties, and performance characteristics. We analyze their resilience against both classical and quantum attacks, discuss their progress in the NIST Post-Quantum Cryptography Standardization process, and evaluate their practical implications and implementation challenges. The discussion emphasizes the provable security, versatility, and efficiency of lattice-based methods, positioning them as the robust and essential successor to RSA for safeguarding digital communications and data in a quantum-enabled future.
Ever since the appearance of quantum computers, prime factoring and discrete logarithm-based cryptography have been questioned, giving birth to the so-called post-quantum cryptography. The most prominent field in post-quantum cryptography is lattice-based cryptography, protocols that are proved to be as difficult to break as certain hard lattice problems like Learning with Errors (LWE) or Ring Learning with Errors (R-LWE). Furthermore, the application of cryptographic techniques to different areas, like electronic voting, has also nourished a great interest in distributed cryptography. In this work, we will give two original threshold protocols based in the lattice problem R-LWE: one for key generation and one for decryption. We will prove them both correct and secure under the assumption of hardness of some well-known lattice problems. Finally, we will give a rough implementation of the protocols in C to give some tentative results about their viability, in particular our model generates keys in the order of 103 ms and decrypts and encrypts in the order of 102 ms.
The emergence of quantum computing poses a fundamental threat to current public key cryptographic systems. This threat is necessitating a transition to quantum resistant cryptographic alternatives in all the applications. In this work, we present the implementation of a practical hybrid end-to-end encryption system that combines classical and post-quantum cryptographic primitives to achieve both security and efficiency. Our system employs CRYSTALS-Kyber, a NIST-standardized lattice-based key encapsulation mechanism, for quantum-safe key exchange, coupled with AES-256-GCM for efficient authenticated symmetric encryption and SHA-256 for deterministic key derivation. The architecture follows a zero-trust model where a relay server facilitates communication without accessing plaintext messages or cryptographic keys. All encryption and decryption operations occur exclusively at client endpoints. The system demonstrates that NIST standardized post-quantum cryptography can be effectively integrated into practical messaging systems with acceptable performance characteristics, offering protection against both classical and quantum adversaries. As our focus is on implementation rather than on novelty, we also provide an open-source implementation to facilitate reproducibility and further research in post quantum secure communication systems.
Post-quantum cryptography (PQC) must secure large-scale communication systems against quantum adversaries where classical hardness alone is insufficient and purely quantum schemes remain impractical. Lattice-based key encapsulation mechanisms (KEMs) such as CRYSTALS-Kyber provide efficient quantum-resistant primitives but rely solely on computational hardness assumptions that are susceptible to hybrid classical-quantum attacks. To overcome this limitation, we introduce the first Clauser-Horne-Shimony-Holt (CHSH)-certified Kyber protocol, which embeds quantum non-locality verification directly within the key exchange phase. The proposed design integrates CHSH entanglement tests using Einstein-Podolsky-Rosen (EPR) pairs to yield measurable quantum advantage values exceeding classical correlation limits, thereby coupling information--theoretic quantum guarantees with lattice-based computational security. Formal reductions demonstrate that any polynomial-time adversary breaking the proposed KEM must either solve the Module Learning With Errors (Module-LWE) problem or a Quantum Merlin-Arthur (QMA)-complete instance of the 2-local Hamiltonian problem, under the standard complexity assumption QMA ⊂ NP. The construction remains fully compatible with the Fujisaki-Okamoto (FO) transform, preserving chosen-ciphertext attack (CCA) security and Kyber's efficiency profile. The resulting CHSH-augmented Kyber scheme therefore establishes a mathematically rigorous, hybrid post-quantum framework that unifies lattice cryptography and quantum non-locality to achieve verifiable, composable, and forward-secure key agreement.
As the advent of quantum computing threatens traditional cryptographic protocols, hybrid classical-quantum secure communication infrastructures have emerged as a critical frontier in cybersecurity. This paper explores the integration of post-quantum cryptographic algorithms—specifically CRYSTALS-Kyber for key encapsulation and CRYSTALS-Dilithium for digital signatures—into hybrid communication architectures designed to resist quantum-level attacks. Leveraging lattice-based cryptographic primitives, both algorithms have been selected for standardization by NIST due to their robust security and performance characteristics. This study evaluates their implementation in real-world communication stacks, assesses latency and throughput under hybrid channel configurations, and proposes a layered security architecture combining classical and quantum-resilient mechanisms. Furthermore, it examines key management, digital trust, and infrastructure scalability in a post-quantum context. Simulation results and hardware-based validations are used to determine practical deployment feasibility in critical sectors such as finance, defense, and healthcare. The findings offer a comprehensive framework for securing data in transitional computing eras, ensuring forward secrecy, and maintaining operational integrity against future adversarial quantum threats.