The Smart City (SC) paradigm has been proposed to address the problem of fast urbanization and the worldwide motivation toward the realization of a set of globally agreed-upon sustainable development goals. However, the actual implementation of SCs faces several significant challenges: (1) managing the complex structures of interdependency that arise from cross-sector integration is a major challenge; (2) ensuring that sensitive data shared within an SC are safe and private; and (3) the availability of real-time risk and interdependency analysis instead of traditional offline modeling and simulation methods against the propagation of run-time failures such as cascade and feedback effects. To the best of our knowledge, there is a lack of research that focuses on cyber cross-sector integration and its mentioned consequences. To fill these research gaps, we suggest a blockchain-based framework called SCADA-NET for integrating different sectors within SCs. This is an important part of making SCs reliable and sustainably long-lasting on the basis of well-known algorithms from the Complex Networks Theory (CNT). A preliminary prototype for SCADA-NET was developed, and the details of its design, implementation, performance evaluation, and future improvements are provided and discussed in this paper. A consortium blockchain allows people to share data in a safe and open way, and CNT models complicated CI networks. This study revealed that these two tools can work effectively together to make cross-sector integration into SCs easy and long-lasting. We also discuss future enhancements for SCADA-NET, including scalability and applicability in the context of urban metaverses.

Abstract Medical information plays an essential task in our everyday lives, in which medical data privacy and security constitute an important issue. The confidentiality of medical data can be achieved by applying one or more encryption and data hiding methods. Amidst the development of quantum computers, most medical data confidentiality techniques may be hacked because their construction is based on mathematical models. Most medical data have a long lifetime exceeding 25 years. Therefore, it is an important issue to design a new medical data hiding technique that has the capability to withstand the probable attacks from the side of quantum or digital devices. In this article, we aim to present a novel medical image steganography strategy based on quantum walks, chaotic systems, and particle swarm optimization algorithm. A 3-D chaotic system and quantum walks are utilized for operating particle swarm optimization algorithm, in which the generated velocity sequence is utilized for substituting the confidential data, and the position sequence is utilized for selecting which position in the hosting image will be employed to host the substituted confidential data. The payload capacity of the suggested mechanism is 2 bits per 1 byte, and the average value for PSNR is 44.1, which is big enough for the naked eye to not differentiate the difference between the carrier image and its stego one.

Data security plays a significant role in data transfer in cloud-based smart cities. Chaotic maps are commonly used in designing modern cryptographic applications, in which one-dimensional (1D) chaotic systems are widely used due to their simple design and low computational complexity. However, 1D chaotic maps suffer from different kinds of attacks because of their chaotic discontinuous ranges and small key-space. To own the benefits of 1D chaotic maps and avoid their drawbacks, the cascading of two integrated 1D chaotic systems has been utilized. In this paper, we report an image cryptosystem for data transfer in cloud-based smart cities using the cascading of Logistic-Chebyshev and Logistic-Sine maps. Logistic-Sine map has been utilized to permute the plain image, and Logistic-Chebyshev map has been used to substitute the permuted image, while the cascading of both integrated maps has been utilized in performing XOR procedure on the substituted image. The security analyses of the suggested approach prove that the encryption mechanism has good efficiency as well as lower encryption time compared with other related algorithms.

Fifth generation (5G) networks are the base communication technology for connecting objects in the Internet of Things (IoT) environment. 5G is being developed to provide extremely large capacity, robust integrity, high bandwidth, and low latency. With the development and innovating new techniques for 5G-IoT, it surely will drive to new enormous security and privacy challenges. Consequently, secure techniques for data transmissions will be needed as the basis for 5G-IoT technology to address these arising challenges. Therefore, various traditional security mechanisms are provided for 5G-IoT technologies and most of them are built on mathematical foundations. With the growth of quantum technologies, traditional cryptographic techniques may be compromised due to their mathematical computation based construction. Quantum walks (QWs) is a universal quantum computational model, which possesses inherent cryptographic features that can be utilized to build efficient cryptographic mechanisms. In this paper, we use the features of quantum walk to construct a new S-box method which plays a significant role in block cipher techniques for 5G-IoT technologies. As an application of the presented S-box mechanism and controlled alternate quantum walks (CAQWs) for 5G-IoT technologies a new robust video encryption mechanism is proposed. As well as to fulfill needs of encryption for varied files in 5G-IoT, we utilize the features of quantum walk to propose a novel encryption strategy for secure transmission of sensitive files in 5G-IoT paradigm. The analyses and results of the proposed cryptosystems show that it has better security properties and efficacy in terms of cryptographic performance.

In this paper, a novel quantum encryption algorithm for color image is proposed based on multiple discrete chaotic systems.The proposed quantum image encryption algorithm utilize the quantum controlled-NOT image generated by chaotic logistic map, asymmetric tent map and logistic Chebyshev map to control the XOR operation in the encryption process.Experiment results and analysis show that the proposed algorithm has high efficiency and security against differential and statistical attacks.