Encrypted control has been extensively studied to ensure the confidentiality of system states and control inputs for networked control systems. This paper presents a computationally efficient encrypted control framework for networked systems enabled by quantum communication. A quantum channel between sensors and actuators is used to generate identical secret keys, whose security is further enhanced through quantum key distribution. These keys enable lightweight encryption and decryption while preserving confidentiality and control accuracy. We develop a novel encryption-decryption architecture for state-feedback control of linear systems based on quantum keys, and characterize the impact of quantum state errors on closed-loop stability. In particular, we establish the existence of a critical threshold on intrinsic quantum noise below which stability is guaranteed. In contrast to classical encrypted control schemes, which may collapse under a single key-bit error, the proposed quantum encrypted control exhibits strong robustness to key imperfections. We further adopt quantization techniques to address the scenarios with limited communication bits in practical situations, and implement privacy protection for quantum keys based on a stochastic quantizer. These results demonstrate that integrating quantum technologies into control systems in a nontrivial and principled manner, even at their current level of maturity, can yield substantial performance gains in reducing computational complexity and improving resilience to key errors while ensuring security against multiple eavesdropping sources.
Encrypted control has been extensively studied to ensure the confidentiality of system states and control inputs for networked control systems. This paper presents a computationally efficient encrypted control framework for networked systems enabled by quantum communication. A quantum channel between sensors and actuators is used to generate identical secret keys, whose security is further enhanced through quantum key distribution. These keys enable lightweight encryption and decryption while preserving confidentiality and control accuracy. We develop a novel encryption-decryption architecture for state-feedback control of linear systems based on quantum keys, and characterize the impact of quantum state errors on closed-loop stability. In particular, we establish the existence of a critical threshold on intrinsic quantum noise below which stability is guaranteed. In contrast to classical encrypted control schemes, which may collapse under a single key-bit error, the proposed quantum encrypted control exhibits strong robustness to key imperfections. We further adopt quantization techniques to address the scenarios with limited communication bits in practical situations, and implement privacy protection for quantum keys based on a stochastic quantizer. These results demonstrate that integrating quantum technologies into control systems in a nontrivial and principled manner, even at their current level of maturity, can yield substantial performance gains in reducing computational complexity and improving resilience to key errors while ensuring security against multiple eavesdropping sources.
This paper presents a novel approach to enhancing the security of Quantum Key Distribution (QKD) protocols by leveraging multi-partite entangled states and dynamic entanglement control. Current QKD protocols, while providing theoretical security guarantees, remain vulnerable to sophisticated attacks that exploit imperfections in quantum hardware and potential eavesdropping strategies. Our work addresses this limitation by introducing a framework where multiple entangled states are employed simultaneously, and their entanglement is dynamically adjusted during the key distribution process. This dynamic control mitigates the impact of noise and reduces the effectiveness of various attack vectors, including those targeting Bell inequality violations and time-dependent attacks. We formally analyze the security of this enhanced protocol, demonstrating its resilience against a broader range of attacks. The key contributions lie in the development of a robust protocol architecture and the implementation of a sophisticated control mechanism that maintains entanglement fidelity and security even under adverse conditions. The proposed method significantly improves the practical security of QKD systems, paving the way for more reliable and secure quantum communication networks.
Cyber-security has become vital for modern networked control systems (NCS). In this paper, we propose that the emerging technology of quantum key distribution (QKD) can be applied to enhance the privacy and security of NCS up to an unbreakable level. QKD can continuously distribute random secret keys with much higher privacy between communication parties, and thus enable the one-time pad encryption that cannot be truly applied in classical networks. We show that the resulting overall security of NCS can be essentially improved, and present a composable definition of security based on the analysis of the key generation and management processes. Moreover, because the security is mainly determined by quantum keys rather than the complexity of encryption algorithms, the control performance can be improved as well by reducing the time delay using simpler algorithms. These advantages are demonstrated by the example of a remotely controlled servo system, showing that the introduction of QKD to NCS can simultaneously improve the security and performance by using the simplest encryption algorithm XOR. Furthermore, we propose a novel Kalman-filter embedded communication protocol that can more efficiently use the raw keys generated by QKD.
The accelerating development of quantum computing capabilities poses an unprecedented challenge to conventional encryption methodologies that currently underpin global digital security infrastructure. Classical cryptographic systems, including widely adopted standards such as RSA and AES, derive their security from the computational intractability of specific mathematical problems, a foundation that quantum algorithms threaten to fundamentally undermine. This research presents a comprehensive investigation into the practical implementation of Quantum Key Distribution as a transformative approach to establishing unconditionally secure communication channels. Through experimental deployment of the BB84 protocol augmented with advanced quantum error correction and privacy amplification techniques, we systematically evaluate the performance characteristics and security guarantees of QKD in realistic network environments. Our experimental framework achieves a secure key generation rate of 2.5 megabits per second while maintaining an average quantum bit error rate of 3.2 percent, demonstrating the practical viability of quantum-secured communication. The implementation exhibits exceptional eavesdropping detection capabilities with a 98.5 percent success rate in identifying unauthorized interception attempts. Comparative security analysis reveals that QKD-based encryption reduces vulnerability to brute-force attacks by 65 percent when contrasted with classical encryption standards. The integration of lattice-based post-quantum cryptographic algorithms provides an additional security layer against store-now-decrypt-later attack strategies. These findings substantiate the position of Quantum Key Distribution as a cornerstone technology for next-generation cybersecurity frameworks, offering robust protection against both current threats and the anticipated capabilities of large-scale quantum computers.
The cyber-security of multi-agent control systems has become vital in practice. To protect the communication process between the individual agents over TCP/IP networks, one must encrypt the messages to be sent, which is costly in a large-scale network when high-level security is demanded. To lessen the burden of heavy encryption and decryption processes, we introduce the Homomorphic Encryption to reduce the number of encryption/decryption terminals that are supposed to equip with every agent. The security is enhanced by the quantum key distribution technology, which can generate secret keys that are theoretically absolutely secure even against quantum computation. We proposed a hybrid method that make good use of the randomness of quantum keys, one-time pad and symmetric encryption to make sure the overall security of homomorphic encryption algorithms. Numerical simulations are provided to illustrate how our scheme.
The resource limitations of IoT nodes and the vulnerability of wireless channels to cyberattacks and snooping, the quick spread of Internet of Things (IoT) devices in wireless surroundings has created serious challenges to data security and privacy. The development of quantum computing, which can meritoriously crack classical encryption, is posing a growing threat to recognized cryptographic techniques like RSA and ECC. By applying concepts from quantum mechanics like predicament cloning, quantum cryptography, in particular Quantum Key Distribution (QKD), provides tentatively unbreakable security. In order to integrate lightweight quantum key exchange with traditional IoT communication protocols, this paper proposes a comprehensive Quantum Cryptography Framework (QCF) exactly designed for Wireless IoT networks. The framework is made to preserve energy efficiency while certifying forward secrecy, confidentiality, integrity, and authentication. A performance evaluation in terms of latency, throughput, and resistance to quantum attacks supports our discussion of the architecture, working mechanism, and implementation deliberations. The findings show that, when compared to traditional encryption methods, the suggested QCF greatly improves the security of wireless IoT systems, certifying resilience against oppositional models of the future.
Quantum secure communication technology, grounded in the principles of quantum mechanics, has revolutionized traditional cryptographic methods, which predominantly rely on mathematical algorithms and logical transformations. Quantum key distribution (QKD) facilitates the secure sharing of symmetric keys between legitimate parties, ensuring the integrity and confidentiality of information in communication channels. Among various QKD schemes, continuous variable quantum key distribution (CV-QKD) has emerged as a viable alternative to the more established discrete variable quantum key distribution (DV-QKD). CV-QKD boasts several advantages, including straightforward deployment, reduced operational costs, and stable signal quality, positioning it as a significant component of the quantum communication landscape. Quantum noise stream cipher (QNSC) represents a technique that employs redundant data streams to encrypt plaintext. Notably, QNSC shares structural similarities with the optical path used in quantum key distribution, allowing for compatibility with existing QKD infrastructure. Furthermore, the keys generated through quantum key distribution ensure absolute security, enabling them to substitute the data streams produced by pseudo-random sequences traditionally used in classical encryption schemes. This substitution enhances the overall security framework of the quantum noise stream encryption approach. The quantum access network (QAN) extends quantum key distribution capabilities from point-to-point connections to point-to-multipoint configurations, thereby becoming an essential component of contemporary network architectures. By interlinking multiple end users with a network backbone, quantum access networks can seamlessly integrate with quantum key distribution protocols. This integration offers a cost-effective and scalable solution for user access to the network. Extensive experimental verifications have demonstrated the viability of downstream access networks, indicating that the merging of quantum access network structures with quantum stream encryption technologies can yield a comprehensive quantum experimental platform. On this platform, security keys are derived through quantum key distribution, which subsequently facilitates the encryption of plaintext information. Notably, experimental validations involving eight users have been successfully executed on this platform, underscoring its practical applicability and effectiveness.