The development of an efficient quantum computer with enough qubits will benefit humanity, but it will also pose a threat to most public cryptography. Even information secured by public cryptography primitives before the advent of this quantum computer falls under this threat since large quantities of data can be eavesdropped and stored by a malicious actor in hopes of someday having access to a quantum computer that will enable the compromising of the data. PQC and QKD are the main answers to this threat. Even though PQC algorithms aim to transition the existing PKI to be quantum-safe, they still offer the same security guarantees as today’s algorithms offer under a classical setting but rely on a new set of mathematical problems believed not to be vulnerable to a quantum computer. PQC is considered by many to be the main solution for most use cases because its integration carries little to no monetary costs, it calls for no major infrastructure updates, and it can be applied to all applications of public cryptography such as key exchanges and digital signatures. On the other hand, QKD leverages the fundamental laws of quantum mechanics to securely distribute cryptographic keys between remote parties. This solution offers information theoretical security and enables perfect forward secrecy, but it demands the development of a whole new type of network, a QKDN, to normalize the generation, distribution, and usage of quantumgenerated symmetric and oblivious keys. This dissertation presents the approach, implementation, and discussion of two quantum-enabled hybrid services, one applied for secure communications, and the other for secure computations. While the main focus was on the integration of quantum-generated keys into these services, PQC, and classical cryptography were also leveraged as recommended by EU’s commission. Regarding secure communications, a key rotator was developed showing how an existing highly deployed VPN solution can be quantum-enabled in a non-intrusive manner with zero downtime and no performance impact. Regarding secure computations, it was explored how quantum-generated oblivious keys can be leveraged in existing OT-based SMC protocols, integrating the solution into an opensource SMC library, its usage in an SMC service infrastructure, and showcased in the scope of two use cases in the fields of medicine and defense. These services were used in the context of a 5-node test network deployed in Aveiro leveraging both research and commercial QKD Modules, demonstrating the viability of the solutions.
The development of an efficient quantum computer with enough qubits will benefit humanity, but it will also pose a threat to most public cryptography. Even information secured by public cryptography primitives before the advent of this quantum computer falls under this threat since large quantities of data can be eavesdropped and stored by a malicious actor in hopes of someday having access to a quantum computer that will enable the compromising of the data. PQC and QKD are the main answers to this threat. Even though PQC algorithms aim to transition the existing PKI to be quantum-safe, they still offer the same security guarantees as today’s algorithms offer under a classical setting but rely on a new set of mathematical problems believed not to be vulnerable to a quantum computer. PQC is considered by many to be the main solution for most use cases because its integration carries little to no monetary costs, it calls for no major infrastructure updates, and it can be applied to all applications of public cryptography such as key exchanges and digital signatures. On the other hand, QKD leverages the fundamental laws of quantum mechanics to securely distribute cryptographic keys between remote parties. This solution offers information theoretical security and enables perfect forward secrecy, but it demands the development of a whole new type of network, a QKDN, to normalize the generation, distribution, and usage of quantumgenerated symmetric and oblivious keys. This dissertation presents the approach, implementation, and discussion of two quantum-enabled hybrid services, one applied for secure communications, and the other for secure computations. While the main focus was on the integration of quantum-generated keys into these services, PQC, and classical cryptography were also leveraged as recommended by EU’s commission. Regarding secure communications, a key rotator was developed showing how an existing highly deployed VPN solution can be quantum-enabled in a non-intrusive manner with zero downtime and no performance impact. Regarding secure computations, it was explored how quantum-generated oblivious keys can be leveraged in existing OT-based SMC protocols, integrating the solution into an opensource SMC library, its usage in an SMC service infrastructure, and showcased in the scope of two use cases in the fields of medicine and defense. These services were used in the context of a 5-node test network deployed in Aveiro leveraging both research and commercial QKD Modules, demonstrating the viability of the solutions.
Quantum computing represents a transformative advancement in computational power, with profound implications for cryptographic systems. This paper explores the intersection of quantum computing and cryptography, examining the potential for quantum computers to both break traditional cryptographic algorithms and enable new forms of secure communication. Classical cryptographic systems, such as RSA and ECC, rely on the computational difficulty of problems like integer factorization and discrete logarithms. However, quantum algorithms, notably Shor's algorithm, can solve these problems exponentially faster than the best-known classical algorithms, posing a significant threat to the security of current cryptographic practices. This vulnerability necessitates the development and implementation of quantum-resistant algorithms to ensure data security in a post-quantum world. The paper reviews the state-of-the-art in quantum-resistant cryptographic algorithms, including lattice-based, hash-based, code-based, and multivariate polynomial cryptography. These algorithms are analyzed for their security properties, efficiency, and practicality for real-world deployment. Additionally, the paper discusses the ongoing standardization efforts led by organizations such as NIST, which are crucial for establishing widely accepted quantum-safe cryptographic protocols. Beyond the threat posed by quantum computing, this paper also highlights the potential benefits quantum computing can bring to cryptographic systems. Quantum Key Distribution (QKD) is one such advancement, offering theoretically unbreakable encryption by leveraging the principles of quantum mechanics. QKD enables secure communication channels that are immune to any computational advances, including those of quantum computers, by ensuring that any attempt at eavesdropping can be detected. The practical implementation challenges of QKD and other quantum cryptographic protocols are also addressed, including issues related to transmission distance, error rates, and integration with existing communication infrastructures. Experimental results from recent QKD trials are presented, showcasing significant progress in extending the viability of quantum-secure communication over long distances. Furthermore, the paper delves into the hybrid approaches combining classical and quantum cryptographic techniques. These approaches aim to leverage the strengths of both paradigms to enhance security and performance. For instance, hybrid protocols might use classical encryption for bulk data transfer, supplemented by quantum techniques for key exchange, thereby ensuring robust security even against future quantum adversaries. In conclusion, while quantum computing poses substantial risks to existing cryptographic systems, it also offers novel opportunities for creating highly secure communication protocols. The transition to quantum-safe cryptography is imperative to protect sensitive information in the quantum era. This paper underscores the urgency of advancing quantum-resistant cryptographic research, promoting international collaboration for standardization, and exploring innovative applications of quantum technologies in cryptography. Continued research and development in these areas are essential to stay ahead of the evolving threat landscape and harness the full potential of quantum computing for secure communications.
Quantum computing is posing a serious risk to classical cryptographic tools such as RSA and ECC as sophisticated quantum algorithms are able to crack their mathematical foundation in a time bound that is a a polynomial in the number of repetitions. In this paper, we will describe the process of integrating Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD) into a hybrid approach to secure communications in the post-quantum world. The suggested methodology is a combination of the computational efficiency and scalability of PQC and the information-theoretic security and eavesdropping detection abilities of QKD. Simulation observations indicate that PQC-only systems are both faster in generating keys and scalable, but do not have a strong eavesdropping detection. On the other hand, non-conditional security is only a feature of systems based on QKD, but it is also highly overhead and slows down key rate. The hybrid PQC-Q KD model provides a balanced performance, high resilience, high authentication, high confidentiality, and realistic deployability. On balance, this discussion demonstrates that the hybrid approach is better than standalone methods and can provide a strong solution to protect against new quantum threats. The large-scale network protocol can be optimized, resources and further integration with other emerging technologies, such as 5G/6G, IoT or cloud computing, can be directed in future research.
In an era of unprecedented technological advancement, the rise of quantum computing poses both opportunities and challenges to network security. While quantum computers promise to revolutionize data processing and problem-solving, they also render traditional cryptographic protocols vulnerable, threatening the integrity of current network security systems. Quantum cryptography, particularly quantum key distribution (QKD), emerges as a groundbreaking solution, leveraging the principles of quantum mechanics to ensure unparalleled data security. Unlike classical methods, QKD guarantees secure communication by detecting eavesdropping attempts, as any observation of quantum states disrupts their integrity. This paper explores the pivotal role of quantum cryptography in shaping future network security protocols amidst a landscape of increasing cyber threats. It provides a comprehensive analysis of QKD systems, their integration into existing infrastructure, and their resilience against potential quantum-based attacks. The discussion includes real-world implementations, such as satellite-based QKD networks and fiber-optic quantum communication systems, illustrating their practical viability and scalability. Furthermore, the paper addresses current challenges, including cost, technical complexity, and interoperability with classical networks, offering insights into ongoing research aimed at overcoming these hurdles. As global reliance on digital infrastructure grows, the transition to quantum-resilient security frameworks becomes imperative. Policymakers, industry leaders, and technology developers must collaborate to advance quantum cryptographic technologies and ensure their accessibility. By securing communication channels against both classical and quantum threats, quantum cryptography is positioned to redefine the foundations of network security, paving the way for a more secure and interconnected digital future.
Secure Multiparty Computation (SMC) allows multiple individuals, each having their own private data, to perform a computation task without unveiling their data to others. SMC has a wide range of real-life use cases, including machine learning, vehicular networks, banking, defense, and healthcare. However, classical SMC implementations face significant challenges related to both security and efficiency. Classical SMC protocols rely on public-key cryptographic methods, which introduce substantial computational and communication costs. Additionally, these protocols are vulnerable to quantum computer attacks that have the potential to break certain types of cryptographic ciphers, notably those used in RSA. In this thesis, we tackle these challenges by enhancing the security and efficiency of SMC implementations through quantum communication and quantum computing. Quantum communication contributes to enhancing security, while quantum computing, by leveraging quantum processors, offers the potential to significantly improve efficiency. In the quantum communication approach, we propose a Quantum SMC (QSMC) framework that leverages three advanced quantum communication technologies - Quantum Random Number Generation (QRNG), Quantum Key Distribution (QKD), and Quantum Oblivious Key Distribution (QOKD)—in conjunction with a Key Management System (KMS) and the Faster Malicious Arithmetic Secure Computation with Oblivious Transfer (MASCOT) protocol. Exploiting the proposed framework, we implement two essential SMC use cases: Safe Route Departure (SRD) and Drug Solubility Prediction (DSP), applied to vehicular networks and drug discovery, respectively. The SRD facilitates secure vehicular communication, allowing vehicles to safely change lanes and exit routes without compromising sensitive information. We achieved a 97% improvement in efficiency by significantly reducing communication costs, while incurring a moderate 42% increase in computational cost. The DSP, on the other hand, empowers pharmaceutical companies to collaboratively train a Graph Convolutional Network (GCN) to predict the solubility of drug molecules while fully safeguarding their private datasets. During training, the loss function across all parties averaged 0.0046, while the Mean Squared Error (MSE) on the test set is 1.2, indicating effective model learning. Afterwards, exploiting the quantum computing approach, we propose two novel SMC protocols for Boolean function computation resorting to the Measurement Based Quantum Computing (MBQC) approach and single qubits. We implement the proposed schemes on the IBM Qiskit platform and validate their feasibility.
Data protection and information security have been the essence of communication in today's digital era. Authentication and secrecy of secure communication are achieved using key-based cryptographic primitives; the security of which significantly relies upon the underlying computationally complex mathematics. Moreover, these existing cryptographic primitives are considered to be non-deterministic on the basis of the existing computational capabilities. However, the considerable advancements in the development of quantum computers have significantly enhanced parallel computations; thereby, posing a great threat to these existing encryption primitives. Thus, in the future, the physical manifestation of a large successful quantum computer is likely to break all the existing public-key encryption algorithms in no time. This has led to a remarkable surge of interest in propelling quantum mechanics into existence; subsequently, leading cryptographers to research various viable domains to offer quantum-resistant secure communications. Resultantly, quantum cryptography/quantum key distribution has emerged as a futuristic replacement for classical cryptography as it offers unconditionally secure communication along with the inherent detection of any unintended user. Thus, keeping in view the significance of this relatively newer domain of cryptography, this research focuses on presenting a consolidated review of the various Quantum Key Distribution (QKD) protocols. A comparative analysis of the working mechanism of the prominent QKD protocols is presented along with an overview of the various emerging trends that have been proposed to optimize the implementational efficiency of the BB84 protocol.
Large quantum computers will be able to break the cryptographic algorithms on which current secure communications rely on. Post-Quantum Cryptography (PQC) and Quantum key distribution (QKD) are two security technologies that show protection capabilities against the latent quantum threat. While PQC relies on different hard mathematical problems to develop a wide variety of cryptographic operations, QKD is based on quantum physics laws to generate and distribute symmetric cryptographic keys through different QKD protocols. These keys can be used by different applications to perform security transformations. QKD still requires authentication to prevent man-in-the-middle attacks. The hybridization of PQC and QKD is an important step for future secure infrastructures, being able to provide long-term security. In this work we propose authenticated QKD approaches that rely on pre-shared keys and hybrid PQC/QKD alternatives and which are able to securely exchange secret QKD keys through authenticated channels. We identify the different configuration alternatives and their parameters, as well as we develop a wide performance evaluation. Results show that pre-shared keys and PQC-based authentication through Dilithium algorithm are the fastest alternatives. Also, we show the potential of the T12 QKD protocol.