PrivShield-CQ: A chaotic–quantum encryption framework with lightweight authentication for post-quantum secure consumer applications

Quantum Key Distribution (QKD) has emerged as a critical component of secure communication in the post-quantum era. This study provides a comparative security and performance analysis of leading QKD protocols—BB84, E91, and Continuous Variable QKD—using experimental and simulated data from terrestrial and satellite-based implementations. Key metrics such as secret key rate, bit error rate, and resistance to quantum attacks are analyzed. Regression and predictive modeling are used to quantify performance decay over distance and noise. The results indicate BB84's robustness and broad applicability, while CV-QKD offers throughput advantages in short-range networks. Keywords: Quantum Key Distribution, QKD, BB84, E91, Continuous Variable QKD, Cryptographic Security, Quantum Communication, Post-Quantum Security

Abstract: Scalable quantum networks, powered by entanglement-driven secure communication, are poised to revolutionize global information exchange, cybersecurity, and quantum computing infrastructures. Unlike classical communication systems, quantum networks leverage quantum entanglement and superposition to enable ultra-secure data transmission, quantum key distribution (QKD), and instantaneous information sharing across large-scale networks. This research explores the fundamental principles of entanglement-based communication, the role of quantum repeaters, quantum memory, and multi-nodal entanglement distribution in overcoming photon loss, decoherence, and distance limitations in quantum networks. Additionally, it examines the hybrid integration of quantum-classical networking architectures, real-world experimental implementations such as satellite-based quantum communication and metropolitan-scale quantum cryptography, and the scalability challenges related to hardware, error correction, and network synchronization. The study also addresses post-quantum cryptography, quantum-resistant algorithms, and cybersecurity vulnerabilities in quantum communication, offering a comprehensive roadmap for the development of secure, scalable, and globally interconnected quantum networks. Keywords: Scalable quantum networks, quantum entanglement, entanglement distribution, quantum key distribution (QKD), secure communication, quantum repeaters, quantum memory, photon loss mitigation, quantum cryptography, post-quantum security, hybrid quantum-classical networks, metropolitan-scale quantum networks, satellite-based quantum communication, quantum internet, quantum coherence, quantum error correction, quantum teleportation, multi-nodal quantum entanglement, cybersecurity in quantum networks, quantum-resistant algorithms.

Quantum key distribution (QKD) enables unconditionally secure communication between distinct parties using a quantum channel and an authentic public channel. Reducing the portion of quantum-generated secret keys, that is consumed during the authentication procedure, is of significant importance for improving the performance of QKD systems. In the present work, we develop a lightweight authentication protocol for QKD based on a `ping-pong' scheme of authenticity check for QKD. An important feature of this scheme is that the only one authentication tag is generated and transmitted during each of the QKD post-processing rounds. For the tag generation purpose, we design an unconditionally secure procedure based on the concept of key recycling. The procedure is based on the combination of almost universal$_2$ polynomial hashing, XOR universal$_2$ Toeplitz hashing, and one-time pad (OTP) encryption. We demonstrate how to minimize both the length of the recycled key and the size of the authentication key, that is required for OTP encryption. As a result, in real case scenarios, the portion of quantum-generated secret keys that is consumed for the authentication purposes is below 1\%. Finally, we provide a security analysis of the full quantum key growing process in the framework of universally composable security.

Abstract: This book, Quantum Networks and Secure Communication, presents a comprehensive and interdisciplinary investigation into the foundations, architectures, protocols, and security mechanisms underpinning quantum communication networks. Rooted in the principles of quantum mechanics—entanglement, superposition, and the no-cloning theorem—the text develops a conceptual framework that redefines secure data transmission by exploring how quantum states can be reliably distributed across spatially separated nodes. The work begins by establishing theoretical constructs including quantum bits (qubits), quantum teleportation, and entanglement distribution, and proceeds to analyze practical implementations of Quantum Key Distribution (QKD) through discrete-variable and continuous-variable protocols. The methodological approach combines analytical modeling, system simulation, and empirical evaluations of existing global deployments such as China’s Micius satellite, Europe’s OpenQKD, and the U.S. Quantum Internet Blueprint. By integrating cryptographic theory with quantum physics and network engineering, the book identifies key vulnerabilities—including photon number splitting and quantum hacking—and examines countermeasures such as decoy-state methods and device-independent QKD. Key findings emphasize the superiority of quantum-based security over classical cryptography in adversarial environments and underscore the implementation challenges of scalability, synchronization, and interoperability. The book concludes by mapping out future directions toward a fully realized quantum internet, offering regulatory, ethical, and governance perspectives. This work serves as a critical resource for advancing the understanding and application of quantum-secure networks in both academic and policy-making arenas. Keywords Quantum networks, quantum communication, quantum key distribution, entanglement, no-cloning theorem, secure communication, QKD protocols, device-independent QKD, photon number splitting, quantum hacking, quantum internet, quantum cryptography, network architecture, quantum repeaters, quantum interoperability, quantum memory, integrated photonics, post-quantum security, quantum authentication, entanglement distribution, quantum network deployment.

Abstract: This research explores the critical role of quantum superalgebras in advancing AI-driven quantum cryptographic systems. Bridging theoretical algebraic constructs with practical implementation, the study examines how quantum superalgebras—generalizations of Lie superalgebras enriched with graded symmetries—serve as the mathematical foundation for secure and adaptive quantum communication. By integrating artificial intelligence models such as neural networks and reinforcement learning agents, the system dynamically optimizes quantum key distribution (QKD), detects anomalies, and corrects quantum transmission errors. The proposed modular architecture features a quantum encoder, channel monitor, and post-processing engine, each mapped to specific superalgebra elements and AI functions. This synergy of advanced algebraic structures and intelligent automation paves the way for scalable, resilient, and future-proof quantum cryptographic protocols. Keywords: Quantum Superalgebras, AI-Driven Cryptography, Quantum Key Distribution, Lie Superalgebras, Quantum Computing, Algebraic Framework, Reinforcement Learning, Quantum Error Correction, Secure Quantum Communication, Post-Quantum Security

Cryptography is very essential in our daily life, not only for confidentiality of information, but also for information integrity verification, non-repudiation, authentication, and other aspects. In modern society, cryptography is widely used; everything from personal life to national security is inseparable from it. With the emergence of quantum computing, traditional encryption methods are at risk of being cracked. People are beginning to explore methods for defending against quantum computer attacks. Among the methods currently developed, quantum key distribution is a technology that uses the principles of quantum mechanics to distribute keys. Post-quantum encryption algorithms are encryption methods that rely on mathematical challenges that quantum computers cannot solve quickly to ensure security. In this study, an integrated review of post-quantum encryption algorithms is conducted from the perspective of traditional cryptography. First, the concept and development background of post-quantum encryption are introduced. Then, the post-quantum encryption algorithm Kyber is studied. Finally, the achievements, difficulties and outstanding problems in this emerging field are summarized, and some predictions for the future are made.

In the era of the Internet of Things (IoT), the transmission of medical reports in the form of scan images for collaborative diagnosis is vital for any telemedicine network. In this context, ensuring secure transmission and communication is necessary to protect medical data to maintain privacy. To address such privacy concerns and secure medical images against cyberattacks, this research presents a robust hybrid encryption framework that integrates quantum, and classical cryptographic methods. The proposed framework not only secure medical data against cyber threats but also protects the secret security keys. Initially, a Quantum Key Distribution (QKD) is employed to generate a shared key, which is then used to secure the symmetric keys via One-Time Pad (OTP) encryption. Next, bit-planes are extracted from each color component. The rows and columns of the extracted bit-planes are scrambled using random sequences which are generated by a 6D hyperchaotic Chen system and the Ikeda map. To further increase confusion in the original data, multiple-step pixel scrambling operations such as pixel shuffling, pixel value shuffling, and rotational and flipping operations are implemented. After the confusion phase, a combination of affine transformations with non-linear functions, Discrete Cosine Transform (DCT) with complex modulation, Discrete Wavelet Transform (DWT) with random phase modulation, bilinear transformation, and nonlinear polynomial mapping are employed to create diffusion in the scrambled components. These multiple encryption operations aim to maximize randomness in the final ciphertext image. Additionally, to reduce computational complexity, only the Most Significant Bit-Planes (MSBs) are encrypted, as they contain more than 94% of the plaintext information. Several experimental results and analyses are conducted to assess the proposed encryption framework, including entropy analysis, key sensitivity analysis, correlation analysis lossless analysis, and histogram analysis. Furthermore, the framework is tested against various cyberattacks such as brute-force attacks, clipping attacks, and noise attacks on the ciphertext images, to demonstrate its resilience against such threats.

With the exponential growth of cloud data and storage space, cloud security has become one of the interesting research areas of cloud computing servers. Attribute-based encryption is a public key encryption algorithm that allows cloud users to secure their sensitive information in the public cloud servers. Quantum key distribution (QKD) is required to improve the security of communication systems. Quantum cryptographic scheme completely depends on quantum mechanics. The major objective of quantum key distribution is to generate a key that takes part in encryption. Traditional attribute-based encryption models are insecure and possible of key distribution attacks using man-in-the-middle attacks. Also, as the size of the input data increases, traditional ABE models failed to compute efficient secret key due to computational time and network overhead. To overcome these issues, a novel chaotic integrity and quantum key distribution (QKD)-based cipher text policy ABE model is implemented in cloud environment. Experimental results proved that the proposed model has high computation speed, storage overhead and secured key distribution compared to traditional CP-ABE, KPABE and QKD-ABE models.

Around 40 years have passed since the first pioneering works introduced the possibility of using quantum physics to enhance communications safety. Nowadays, quantum key distribution (QKD) exited the physics laboratories to become a mature technology, triggering the attention of States, military forces, banks, and private corporations. This work takes on the challenge of bringing QKD closer to a consumer technology: deployed optical fibers by telecommunication companies of different States have been used to realize a quantum network, the first‐ever connecting three different countries. This work also emphasizes the necessity of networks where QKD can come up besides classical communications, whose coexistence currently represents the main limitation of this technology. This network connects Trieste to Rijeka and Ljubljana via a trusted node in Postojna. A key rate of over 3 kbps in the shortest link and a 7‐hour‐long measurement demonstrate the system's stability and reliability. The network has been used to present the QKD at the G20 Digital Ministers' Meeting in Trieste. The experimental results, together with the interest that one of the most important events of international politics has attracted, showcase the maturity of the QKD technology bundle, placing it in the spotlight for consumer applications in the near term.

The influence of bias current on the bandwidth of chaotic signals in semiconductor lasers by optical feedback has been studied experimentally and numerically. The measured data reveal that the bandwidth increase when the system becomes chaotic and this chaotic signal has a broadband spectrum so it can be used as a carrier for the quantum key. Mixing chaotic signal and quantum key make a very small change in chaotic bandwidth that does not affect the security of data transmitted.

Enhanced Cloud Data Security with Lightweight Chaotic Map and Quantum Key Distribution

In the present era of Internet of Things (IoT), communicating medical reports for the concerted diagnosis plays a vital role in any telemedicine network. Here, security of communication, being one of the most important requirements, needs to be appropriately addressed in protecting the transmitted data to ensure authentication, privacy, trust and integrity. In this context, this chapter suggests an image encryption and authentication algorithm to handle bulky medical images integrated with Quantum encryption mechanism. The proposed Quantum Cyber-physical system is established with the help of the security algorithms along with cloud computing framework. In the proposed encryption scheme, initially, the original classical medical image is converted into Quantum image format using Novel Enhanced Quantum Representation (NEQR). Then using Cellular Automata (CA) (Rule:30), the quantum image is confused and diffused and its authentication is provided by cellular automata. Further, encryption takes place in four stages, namely, key generation, permutation, Deoxyribo Nucleic Acid (DNA) operation and diffusion. Additionally, the cloud framework provides a comprehensive platform for individual access to the encrypted files depending on the access privileges granted to the relevant individuals. The approach is well suited for a versatile hospital management system. The strength of the proposed encryption algorithm is validated by evaluating different metrics like Number of Pixel Change Rate (NPCR), Unified Average Change in Intensity (UACI), correlation, histogram and certain chosen-plaintext attacks.

Secure image transmission is increasingly vital in the digital era, especially against emerging quantum threats. This study proposes a hybrid image encryption scheme that integrates Quantum Key Distribution (QKD) using the BB84 protocol with a combination of 7-dimensional (7D) and 2-dimensional (2D) hyperchaotic systems to achieve robust security. The BB84 protocol facilitates quantum-assisted key exchange, ensuring resistance to eavesdropping, while the hyperchaotic systems provide high entropy and complex randomness, utilized in a layered permutation-substitution encryption framework. The initial seeds for chaotic sequences are derived using a SHA-512 hash of both the input image and quantum-generated key, ensuring uniqueness and sensitivity. Experimental validation was conducted using several benchmark images. The information entropy values of the ciphered images reached up to 7.9993, indicating excellent randomness. Differential analysis showed high resistance to small perturbations, with NPCR exceeding 99.61% and UACI averaging around 33.47%, which meet standard security thresholds. Histogram and chi-square tests confirmed the uniform pixel distribution, with chi-square values below 280, satisfying the randomness criterion for 8-bit images. Furthermore, correlation coefficients of adjacent pixels dropped to near zero, evidencing effective decorrelation. The encryption scheme also demonstrated robustness to data loss, as shown by the successful decryption of partially corrupted cipher images. Robustness testing under partial data loss (200×200-pixel blocks) also demonstrated visual recoverability and algorithm resilience. Overall, the proposed BB84-assisted dual-hyperchaotic encryption scheme offers a secure and computationally effective solution for protecting sensitive image data, making it suitable for post-quantum secure communications.

The industry-based internet of things (IIoT) describes how IIoT devices enhance and extend their capabilities for production amenities, security, and efficacy. IIoT establishes an enterprise-to-enterprise setup that means industries have several factories and manufacturing units that are dependent on other sectors for their services and products. In this context, individual industries need to share their information with other external sectors in a shared environment which may not be secure. The capability to examine and inspect such large-scale information and perform analytical protection over the large volumes of personal and organizational information demands authentication and confidentiality so that the total data are not endangered after illegal access by hackers and other unauthorized persons. In parallel, these large volumes of confidential industrial data need to be processed within reasonable time for effective deliverables. Currently, there are many mathematical-based symmetric and asymmetric key cryptographic approaches and identity- and attribute-based public key cryptographic approaches that exist to address the abovementioned concerns and limitations such as computational overheads and taking more time for crucial generation as part of the encipherment and decipherment process for large-scale data privacy and security. In addition, the required key for the encipherment and decipherment process may be generated by a third party which may be compromised and lead to man-in-the-middle attacks, brute force attacks, etc. In parallel, there are some other quantum key distribution approaches available to produce keys for the encipherment and decipherment process without the need for a third party. However, there are still some attacks such as photon number splitting attacks and faked state attacks that may be possible with these existing QKD approaches. The primary motivation of our work is to address and avoid such abovementioned existing problems with better and optimal computational overhead for key generation, encipherment, and the decipherment process compared to the existing conventional models. To overcome the existing problems, we proposed a novel dynamic quantum key distribution (QKD) algorithm for critical public infrastructure, which will secure all cyber–physical systems as part of IIoT. In this paper, we used novel multi-state qubit representation to support enhanced dynamic, chaotic quantum key generation with high efficiency and low computational overhead. Our proposed QKD algorithm can create a chaotic set of qubits that act as a part of session-wise dynamic keys used to encipher the IIoT-based large scales of information for secure communication and distribution of sensitive information.

In the era of ubiquitous big data, ensuring secure storage, transmission, and processing has become a paramount concern. Classical cryptographic methods face increasing vulnerabilities in the face of quantum computing advancements. This research proposes an enhanced big data security framework integrating a quantum chaotic map of key sequence (QCMKS), which synergizes the principles of quantum mechanics and chaos theory to generate highly unpredictable and non-repetitive key sequences. The system incorporates quantum random number generation (QRNG) for true entropy sources, quantum key distribution (QKD) for secure key exchange immune to eavesdropping, and quantum error correction (QEC) to maintain integrity against quantum noise. Additionally, quantum optical elements transformation (QOET) is employed to implement state transformations on photonic qubits, ensuring robustness during transmission across quantum networks. The integration of QCMKS with QRNG, QKD, QEC, and QOET significantly enhances the confidentiality, integrity, and availability of big data systems, laying the groundwork for a quantum-resilient data security paradigm. While the proposed framework demonstrates strong theoretical potential for improving big data security, its practical robustness and performance are subject to current quantum hardware limitations, noise sensitivity, and integration complexities.