Physically unclonable function (PUF) is a physical unit fabricated inside a sensor and generally considered as an assurance anchor of resource inhibited device. Essentially, the function is based on the cryptographic approach, where a key is created and utilized such that it cannot be cloned. More specifically, it is an arbitrary function, which maps inherent properties of the hardware devices to a unique bit stream of information. Authentication and key agreement (AKA) protocols are widely used in electronic commerce, electronic stock trading, and many secured business transaction platforms, because they allow the communicating devices to mutually authenticate each other while exchanging authenticated session key (or secret key) that can be used subsequently to establish a secured communication channel. Yet, these protocols are also vulnerable to a broad range of security outbreaks. In light of these notions and practical applications, this article is intended to: 1) provide an overview of AKA protocols, PUF plus the combined PUF-based AKA; 2) systematically and taxonomically examine and discuss with pros and cons of AKA applications to the fast growing areas of Internet of Things, wireless sensor networks, and smart grids based on a meticulous survey of the existing literature; 3) summarize the challenges to deployment and potential security risks of the underlying technologies and possible remedies or mitigation strategies; and 4) to conduct and report a comparative performance and security analysis with respect to the three focused areas.

Most of the hospitals store their patient's data locally and some even do not have any backup storage. This poses a real threat of data loss or data corruption. Although many hospitals are migrating to cloud storage, the clouds have their own threat vectors. Recently, various health care providers were hit by ransomware and Distributed Denial of Service attacks during the COVID‐19 outbreak. Due to these attacks, many emergency services were halted, affecting hundreds of thousands without any healthcare. Another problem with these traditional database practices is that they often misplace or mix the patient's data, which, needless to say, have severe complications. Many researchers are working on IPFS and Blockchain technology to improve the storage of medical records. This article presents a detailed study of the IPFS and Blockchain based healthcare secure storage solutions. It analyzes the existing solutions and their architecture, which will further facilitate the future research and development of emerging IPFS and Blockchain technologies.

Industry 4.0 connects the latest technologies such as cloud computing, Internet of things (IoT), machine learning and artificial intelligence (ML/AI), and blockchain to provide more automation in the industrial process and also bridges the gap between the physical and digital worlds through the cyber-physical system. The inherent feature of IoT devices creates the industry to smart industry (referred to as industrial IoT, i.e., IIoT) through its data-driven decision policies. However, several challenges such as decentralization, security and privacy vulnerability, single point of failure (SPOF), and trust issues exist in the IoT system. Blockchain is one of the promising technologies that can bring about opportunities for addressing the challenges of IoT systems. In this article, we have investigated the integration of IoT with blockchain technology and provided an in-depth study of the blockchain-enabled IoT and IIoT systems. The state-of-the-art research is categorized into data storage and management technique, big data and cloud computing technique (finance and data auditing), and industrial sectors (supply chain, energy, and healthcare sector). The insightful discussion based on the different categories is also presented in the paper. In particular, first, we introduce the IoT and IIoT and then discuss the need for smart contracts in IoT and IIoT systems. Next, we concentrate on the convergence of blockchain and IoT with state-of-the-art research. In addition, this article also provides the open and future research directions towards this era with the highlighted observations.

With the growing needs of data across the world, it almost hard to live without data a day. This is almost a blessing in disguise for the researchers working on different domains and dealing with huge amounts of data. The fog computing concept is aiming to change the scenarios created by cloud computing environments and also to make the data‐centric clouds decentralized and localized. Fog devices contain only specific information that is frequently used in it and generally the size of the data in fog device is very less in comparison with cloud server. Fog stores only those data, which are frequently used by the users, rest it takes from the cloud itself. The motivation toward this field to make the data flow in various domain seamless and hassle free. Fog computing can be thought as an intermediate between the users and the cloud server, which connects end users easily and thus reduces the latency of the services. This paper discusses the three layered data flow architecture for fog computing and it proposes several novel architectures such as energy lattices, MediFog, UXFog, connected parking system, and FoAgro to utilize the concept of fog computing.