Quantum-safe public key exchange protocols face significant challenges in hardware- and software-based approaches. Quantum key distribution, which relies on specialized quantum hardware, presents a significant barrier to widespread adoption due to its high cost and limited scalability. Conversely, software-based solutions using post-quantum algorithms introduce complications, such as increased resource demands and larger cipher-texts. Furthermore, the security of these post-quantum algorithms remains relatively untested, which has led to the emerging trend of hybrid deployment, combining clas-sical and quantum-resistant techniques to hedge against potential vulnerabilities. Recently, Arqit proposed a quantum-secure symmet-ric key agreement (SKA) protocol, claiming that it is lightweight and scalable [1] to address these problems. However, their proprietary solution is not available for independent analysis. To evaluate the performance and scalability of quantum-secure SKA techniques, we develop variations of the SKA protocol using open-source and accessible components in this work. To analyze quantum-secure SKA scheme, we imple-mented an SKA technique that involves a hybrid mech-anism, leveraging secret strings distributed through a combination of existing classical and quantum public key pairs during the initial key exchange. We analyze our scheme and demonstrate that it incurs minimal performance overhead, with only 99ms for purely quantum SKA and 199ms for the hybrid version, compared to the classical SKA protocol. We also show that our scheme remains robust under various network conditions, including delays, packet losses, and bandwidth variations, maintaining small and consistent overheads. We also show that this solution is scalable, with an overhead of only one second for every additional five concurrent users. This performance improves significantly with increased computational resources-achieving a 50-60% improvement when scaling from two to four CPUs. Additionally, our security evaluations confirm that the protocol provides consistent and sufficient randomness throughout the key agreement process, ensuring quantum-resistance at every stage.
Quantum-safe public key exchange protocols face significant challenges in hardware- and software-based approaches. Quantum key distribution, which relies on specialized quantum hardware, presents a significant barrier to widespread adoption due to its high cost and limited scalability. Conversely, software-based solutions using post-quantum algorithms introduce complications, such as increased resource demands and larger cipher-texts. Furthermore, the security of these post-quantum algorithms remains relatively untested, which has led to the emerging trend of hybrid deployment, combining clas-sical and quantum-resistant techniques to hedge against potential vulnerabilities. Recently, Arqit proposed a quantum-secure symmet-ric key agreement (SKA) protocol, claiming that it is lightweight and scalable [1] to address these problems. However, their proprietary solution is not available for independent analysis. To evaluate the performance and scalability of quantum-secure SKA techniques, we develop variations of the SKA protocol using open-source and accessible components in this work. To analyze quantum-secure SKA scheme, we imple-mented an SKA technique that involves a hybrid mech-anism, leveraging secret strings distributed through a combination of existing classical and quantum public key pairs during the initial key exchange. We analyze our scheme and demonstrate that it incurs minimal performance overhead, with only 99ms for purely quantum SKA and 199ms for the hybrid version, compared to the classical SKA protocol. We also show that our scheme remains robust under various network conditions, including delays, packet losses, and bandwidth variations, maintaining small and consistent overheads. We also show that this solution is scalable, with an overhead of only one second for every additional five concurrent users. This performance improves significantly with increased computational resources-achieving a 50-60% improvement when scaling from two to four CPUs. Additionally, our security evaluations confirm that the protocol provides consistent and sufficient randomness throughout the key agreement process, ensuring quantum-resistance at every stage.
The increasing reliance on cloud storage across sectors has made the protection of sensitive data a critical concern especially as advances in quantum computing threaten to break traditional public-key cryptographic systems. This growing vulnerability raises urgent questions about how to secure digital assets in a post-quantum future. To address this challenge, this study aims to design, implement, and evaluate a hybrid encryption framework that combines symmetric encryption for data confidentiality with quantum-resistant public-key algorithms for key management and digital signatures. The objective was to develop a secure and practical solution that can be readily adopted using open-source tools. The system was built in a Linux-based virtual environment using an S3-compatible object storage platform, integrated with quantum-safe cryptographic libraries, and automated through scripting. Performance testing was conducted using files ranging from 100 MB to 1 GB, with metrics such as encryption and decryption time, CPU usage, upload/download latency, and internet throughput analyzed. The results showed that while quantum-safe operations added some overhead, even large files could be securely processed in under two minutes with stable system performance and no data corruption. These findings confirm that hybrid encryption models can be deployed today without specialized hardware, offering a forward-compatible and robust approach to cloud security. This work contributes a tested and reproducible framework for early adoption of quantum-safe cryptography in real-world cloud environments.
Aim: The imminent advent of large-scale quantum computers within the next years is expected to highly affect the security of several cryptosystems that are now considered secure; this mainly holds for classical, long-established, public key cryptographic algorithms such as RSA and elliptic curve cryptography. Apparently, any security protocol that relies on such ciphers, including the transport layer security (TLS) protocol which constitutes a somewhat de facto standard for the security on the web, will not be considered secure in the post-quantum era. To alleviate the security risks stemming from quantum computing, several proposals have been submitted to the relevant procedure initiated by NIST towards evaluating and standardizing one or more quantum-resistant public-key cryptographic algorithms. This paper focuses on embedding post-quantum secure cryptographic algorithms into the TLS protocol to analyze its performance. More precisely, the paper aims to analyze whether this transition to post-quantum secure algorithms will have a significant impact on the user experience due to the possible increase of client--server communication times. Methods: Having as the starting point several important works in the field, several experiments were carried out, using combinations of cloud and local virtual machines per case and considering all the post-quantum cryptographic algorithm finalists for key exchange from the third round of the ongoing NIST process, for various cryptographic as well as network parameters. Results: Our results exhibit that, for key exchange in TLS, the best performance among the post-quantum secure ciphers is achieved by the Saber and CRYSTAL-Kyber variants for all security levels, regardless of the underlying computing power. The performance is comparable to that of the corresponding one achieved by a classical elliptic curve algorithm for key exchange for both RTT and packet loss ratio — i.e., the network parameters seem to have the same effect on post-quantum secure algorithms as in the case of a conventional elliptic curve algorithm. However, the effect of the network parameters on the performance is more crucial than the effect of the underlying chosen ciphers. Conclusion: According to the experiments, we conclude that there exist very promising algorithms that could be utilized in TLS in the near future, which may behave even better than the conventional elliptic curve algorithms for key exchange. It should also be pointed out that NIST announced on 5 July 2022 (i.e., after the completion of our research experiments) that, for general encryption used when we access secure websites, the CRYSTALS-Kyber algorithm has been selected, having as one of its advantages the speed of operation. Hence, the results of our paper are fully in line with the progress of the NIST process. Taking into account that the NIST process is still ongoing (now in its fourth round) with the aim to select more algorithms, as well as that some algorithms may be standardized outside NIST, it becomes evident that our results provide very useful insights on performance aspects of the post-quantum secure algorithms.
The rapid development of quantum computing presents a significant challenge to existing cryptographic systems, such as RSA and Elliptic Curve Cryptography, which rely on the complexity of mathematical problems for security. Shor’s algorithm, which can efficiently solve these problems, emphasizes the need for cryptographic solutions that are resistant to quantum threats. This study aims to investigate the potential of Quantum Cryptography, with a specific focus on Quantum Key Distribution (QKD), to strengthen network security in response to emerging quantum computing risks. Despite the theoretical potential of QKD, there remains a gap in its practical application, particularly in terms of scalability, high implementation costs, and sensitivity to environmental factors, which have hindered its widespread adoption. The novelty of this research lies in the comprehensive approach it takes, combining theoretical analysis of QKD protocols, simulations using Qiskit, and comparisons with traditional cryptographic methods. This provides a more robust understanding of QKD effectiveness in different network scenarios. The study reveals that the BB84 protocol consistently outperforms the E91 protocol in terms of key generation efficiency and noise resilience. However, despite its unmatched security capabilities, QKD faces challenges such as scalability and implementation costs. To overcome these challenges and achieve widespread adoption, integrating QKD with post quantum cryptography and developing hybrid approaches are essential. Quantum Cryptography, particularly QKD, holds the potential to become a cornerstone for securing critical infrastructure, ensuring communication security in the quantum era.
Quantum cryptography has emerged as a revolutionary technology for ensuring secure communication in the era of quantum computing. While existing research primarily focuses on theoretical frameworks and small-scale experimental setups, significant challenges remain in practical implementation, scalability, and security vulnerabilities. This study aims to bridge the gap between theory and real-world deployment by developing robust quantum cryptographic protocols that address key challenges such as noise management, side-channel attacks, and Trojan horse attacks. Additionally, we propose an optimized quantum key distribution (QKD) mechanism that ensures secure communication over long distances under realistic conditions. Our research integrates post-quantum cryptography with quantum cryptographic techniques to provide a hybrid security model that is resilient against both classical and quantum computing threats. By leveraging commercially available quantum hardware and advanced randomness extraction methods, this study contributes to the development of scalable, secure, and efficient quantum communication networks. The findings of this research will play a crucial role in advancing secure digital communication systems and fortifying data security in the post-quantum era.
Quantum cryptography has emerged as a revolutionary technology for ensuring secure communication in the era of quantum computing. While existing research primarily focuses on theoretical frameworks and small-scale experimental setups, significant challenges remain in practical implementation, scalability, and security vulnerabilities. This study aims to bridge the gap between theory and real-world deployment by developing robust quantum cryptographic protocols that address key challenges such as noise management, side-channel attacks, and Trojan horse attacks. Additionally, we propose an optimized quantum key distribution (QKD) mechanism that ensures secure communication over long distances under realistic conditions. Our research integrates post-quantum cryptography with quantum cryptographic techniques to provide a hybrid security model that is resilient against both classical and quantum computing threats. By leveraging commercially available quantum hardware and advanced randomness extraction methods, this study contributes to the development of scalable, secure, and efficient quantum communication networks. The findings of this research will play a crucial role in advancing secure digital communication systems and fortifying data security in the post-quantum era.
The advance of quantum computing poses significant risks to traditional cryptographic systems, including RSA and ECC, due to algorithms such as Shor's, prompting an urgent need for robust post-quantum cryptography (PQC) solutions. This paper presents a systematic review of PQC algorithms, encompassing lattice-based, code-based, multivariate polynomial, hash-based, and supersingular isogeny-based cryptography. By evaluating recent publications and NIST standardization efforts, we assess these approaches in terms of quantum resistance, computational efficiency, scalability, and implementation challenges. Lattice-based schemes, notably CRYSTALS-Kyber, excel in quantum-secure encryption and performance, whereas codebased systems like McEliece are hindered by large key sizes. Hash-based signatures, such as SPHINCS+, and isogeny-based protocols, including SIDH, provide promising alternatives but require further optimization to reduce computational overhead. Our analysis highlights the potential of hybrid PQC methods and lightweight hardware implementations for securing emerging domains like IoT, blockchain, and financial systems. The review serves as a foundational resource for researchers and practitioners, advocating the adoption of quantum-resistant cryptography to preserve data confidentiality, integrity, and authenticity in the quantum era.