With the advent of quantum computers, traditional key exchange mechanisms are under threat, necessitating the development of new methods. Recently, Module-Lattice-Based Key Encapsulation Mechanism (ML-KEM) has been standardized as a quantum-safe key exchange method. Another emerging technique is Quantum Key Distribution (QKD) and its most famous protocol, BB84, which relies on the principles of quantum physics to exchange key information. Both techniques are considered secure against attacks by quantum computers, but their security is based on different principles. However, both key exchange types include a statistical component which, if an attacker were lucky, could allow circumventing these underlying hard problems. In this paper, we suggest that as a key exchange mechanism, BB84 should be run with security parameters comparable to those of ML-KEM, and analyze performance implications if this choice is taken. We illustrate the impact by estimating the number of raw bits required to generate a 256-bit symmetric key using BB84 and assessing the resulting performance implications. We further show how the BB84 finite-size security parameter can be chosen such that the post-processing failure probability is of the same order as the cumulative decapsulation-failure probability of ML-KEM. According to our results, the security parameter in BB84 should be at most 2−75.8 if statistical failure probability comparable to the ML-KEM decapsulation-failure target is desired. These findings offer general guidelines for BB84 parameter selection, with hybrid protocol design representing one potential application context.
With the advent of quantum computers, traditional key exchange mechanisms are under threat, necessitating the development of new methods. Recently, Module-Lattice-Based Key Encapsulation Mechanism (ML-KEM) has been standardized as a quantum-safe key exchange method. Another emerging technique is Quantum Key Distribution (QKD) and its most famous protocol, BB84, which relies on the principles of quantum physics to exchange key information. Both techniques are considered secure against attacks by quantum computers, but their security is based on different principles. However, both key exchange types include a statistical component which, if an attacker were lucky, could allow circumventing these underlying hard problems. In this paper, we suggest that as a key exchange mechanism, BB84 should be run with security parameters comparable to those of ML-KEM, and analyze performance implications if this choice is taken. We illustrate the impact by estimating the number of raw bits required to generate a 256-bit symmetric key using BB84 and assessing the resulting performance implications. We further show how the BB84 finite-size security parameter can be chosen such that the post-processing failure probability is of the same order as the cumulative decapsulation-failure probability of ML-KEM. According to our results, the security parameter in BB84 should be at most 2−75.8 if statistical failure probability comparable to the ML-KEM decapsulation-failure target is desired. These findings offer general guidelines for BB84 parameter selection, with hybrid protocol design representing one potential application context.
Key exchange mechanisms are foundational to secure communication, yet traditional methods face challenges from quantum computing. The Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM) is a post-quantum cryptographic key exchange protocol with unknown successful quantum vulnerabilities. This study evaluates the ML-KEM using experimental benchmarks. We implement the ML-KEM in Python for clarity and in C++ for performance, demonstrating the latter’s substantial performance improvements. The C++ implementation achieves microsecond-level execution times for key generation, encapsulation, and decapsulation. Python, while slower, provides a user-friendly introduction to the ML-KEM’s operation. Moreover, our Python benchmark confirmed that the ML-KEM consistently outperformed RSA in execution speed across all tested parameters. Beyond benchmarking, the ML-KEM is shown to handle the computational hardness of the Module Learning With Errors (MLWE) problem, ensuring resilience against quantum attacks, classical attacks, and Artificial Intelligence (AI)-based attacks, since the ML-KEM has no pattern that could be detected. To evaluate its practical feasibility on constrained devices, we also tested the C++ implementation on a Raspberry Pi 4B, representing IoT use cases. Additionally, we attempted to run integration and benchmark tests for the ML-KEM on microcontrollers such as the ESP32 DevKit, ESP32 Super Mini, ESP8266, and Raspberry Pi Pico, but these trials were unsuccessful due to memory constraints. The results showed that while the ML-KEM can operate effectively in such environments, only devices with sufficient resources and runtimes can support its computational demands. While resource-intensive, the ML-KEM offers scalable security across diverse domains such as IoT, cloud environments, and financial systems, making it a key solution for future cryptographic standards.
The rapid advancement of quantum computing poses a serious threat to traditional cryptographic systems such as RSA and Elliptic Curve Cryptography (ECC), which rely on computational difficulty for security. Quantum algorithms like Shor’s and Grover’s have the potential to break or weaken these methods, putting modern communication systems at risk. To address this challenge, this work presents a quantum-safe com-munication framework that combines the BB84 Quantum Key Distribution (QKD) protocol with Post-Quantum Cryptography (PQC) techniques, aiming to ensure secure data exchange in the presence of quantum-capable adversaries. In this system, the BB84 protocol is simulated to enable secure key exchange between two parties over a virtual quantum channel. The generated key is refined through processes such as basis matching, error correction, and privacy amplification using SHA-256 to ensure reliability and secrecy. For secur-ing communication, One-Time Pad (OTP) encryption is used alongside HMAC-SHA3-256 to provide both confidentiality and message integrity. Additionally, file encryption is handled using the XChaCha20-Poly1305 algorithm, selected for its efficiency and strong protection against potential vulnerabilities like nonce reuse. To further enhance security, the framework integrates a hybrid key management approach using the Kyber-512 Key Encapsulation Mechanism (KEM) combined with a Key Deriva-tion Function (KDF), merging classical and quantum-resistant techniques. Experimental results demonstrate the effectiveness of the system, achieving a Quantum Bit Error Rate (QBER) of 2.5% and successful performance in both message and file en-cryption. Overall, this work contributes toward the development of practical and resilient communication systems designed for the emerging quantum era.
Since the security of post-quantum cryptography (PQC) algorithms is based on the hardness of mathematical problems, while the security of quantum key distribution (QKD) relies on the fundamental principles of quantum physics, each approach possesses distinct advantages and limitations that can complement one another. Consequently, recent studies have proposed hybrid schemes that combine QKD and PQC to establish a dual-layered security model. In response to this trend, this study proposes hybrid schemes that integrate QKD with the National Institute of Standards and Technology (NIST) standardized PQC algorithms. These hybrid schemes include two core components: a hybrid QKD-PQC key exchange protocol and a hybrid QKD-PQC digital signature scheme. For the hybrid key exchange protocol, this study combines Module-Lattice-based Key Encapsulation Mechanisms (ML-KEM) with QKD protocols, specifically BB84 and E91, to construct a secure key exchange protocol. In the design of the hybrid digital signature scheme, this study utilizes Module-Lattice-based Digital Signature Algorithms (ML-DSA) and Stateless Hash-based Digital Signature Algorithms (SLH-DSA) to generate signature reconstruction values. These values are verified using confirmation codes transmitted via the BB84 and E91 protocols. The proposed hybrid key exchange protocol is evaluated by examining the shared secret key it produces, particularly with respect to entropy and whether the output is independent and identically distributed (IID). Furthermore, the computation time and message lengths of the proposed hybrid schemes are evaluated.
Quantum cryptography, especially quantum key distribution (QKD), is significant for shielding communications against the dangers of quantum computing by providing information-theoretic security established in quantum mechanics. To securely generate and distribute cryptographic keys between two parties, several quantum safe protocols were proposed. Even though the BB84 protocol is a more trusted, widely implemented and standardized protocol for QKD, it suffers from 50% key loss during sifting. The next version B92 protocol is the lighter version of BB84, has critical issues such as: less tolerance to noise and photon loss and is specifically applicable for short range, lower security scenarios and as B92 has only two non-orthogonal states, it makes it more vulnerable to certain Unambiguous State Discrimination (USD) attacks. Hence, this work has taken the most widely adopted protocol BB84 as it has more advantages for underwater networks by proposing a novel hybrid approach to mitigate the fundamental efficiency challenge of key losses during the sifting phase due to basis mismatches. As this inefficiency is a significant barrier to practical deployment, particularly in resource-constrained environments like underwater networks, we propose a novel hybrid KEM-QKD protocol that eliminates the sifting process of BB84 entirely. Our primary contributions are: (i) integration of a post-quantum key encapsulation mechanism (KEM), CRYSTALS-Kyber, to securely transmit basis information prior to measurement which allows for 100% basis alignment between communicating parties, preserving the entire raw key; (ii) benchmarked our modified protocol against traditional BB84 using NetSquid, a quantum network simulator and (iii) optimized the proposed protocol’s parameters using Bayesian Optimization (BO) and Genetic Algorithms (GA). Our results demonstrate two major performance enhancements: (i) a 100% raw key generation rate, a significant improvement over BB84’s 50% efficiency and (ii) an increase in the maximum secure distance of up to 42% in existing optic fiber cables, with BO proving superior for parameter optimization. Further, our rigorous experimentation results showcase the potential of the proposed hybrid quantum-classical framework to enhance the practical efficiency of QKD, advancing its viability for robust, high-performance underwater quantum networks.
In the era of rapid development of quantum computers and post-quantum algorithms, basic cryptographic algorithms like RSA (Rivest-Shamir-Adleman) become vulnerable, especially under the influence of possible factorization by Shor's algorithm. This research work analyzes safety challenges and possible hazards caused by quantum attacks on the RSA, while also presenting ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) as a convenient, standardized post-quantum algorithm that secures the safe exchange of keys. Besides the fundamental theoretical basis, the research work presents a clear demonstration of the technical implementation of the ML-KEM algorithm, including its architecture and principles of operation. Also, this research work compares the performances of ML-KEM and RSA algorithms using modern processor architecture, pointing out their superiority in the aspects of speed and energy efficiency. Furthermore, possible challenges caused by the migration of existing systems are presented.
This paper describes a hybrid key-encapsulation mechanism (KEM): a way for two parties to agree on a shared 32-byte secret that stays safe as long as either of two very different building blocks remains unbroken. The first building block is classical RSA-2048. The second is ML-KEM-768, the lattice-based KEM that NIST standardized as FIPS 203. We run both, then mix their two secrets with HKDF-SHA-256 to produce one session key. The pay-off is simple: an attacker has to break both RSA and ML-KEM to learn the session key, so the scheme protects you today (when RSA is strong) and continues to protect you after a quantum computer breaks RSA (when ML-KEM carries the load). A second, independent idea appears here only as an engineering optimization: the Furui 6n±1 sieve, a fast way to generate RSA primes. We are explicit that the sieve contributes nothing to security — it just makes classical key generation cheaper during the migration period, when systems keep minting new RSA keys. We prove this carefully so that no reader mistakes a performance trick for a security feature. The paper is written for engineers who want to deploy a hybrid KEM correctly. The main text explains the construction, the threat model, and how to implement it safely. The appendices give the full formal security reduction, the statistical validation of the sieve, and a reproducible benchmark methodology for readers who want the underlying detail.