The blockchain technology first emerged with the Bitcoin whitepaper, which was the first successful proposal to implement a decentralized digital currency with ability to execute completely non-reversible transactions without a trusted and centralized third party. Blockchain concept provided an inherent part of this decentralization together with hash-based proof-of-work, public key cryptography, and peer-to-peer network. Even though blockchain technology was introduced to solve the double-spending problem of electronic money without relying on a trusted third party, this particular concept is being researched and already used to solve problems in many other areas. This paper captures concepts of blockchain, its applications, issues, and suggested improvements referring to blockchain-related subsequent publications.

The rapid development and the expansion of Internet of Things (IoT)-powered technologies have strengthened the way we live and the quality of our lives in many ways by combining Internet and communication technologies through its ubiquitous nature. As a novel technological paradigm, this IoT is being served in many application domains including healthcare, surveillance, manufacturing, industrial automation, smart homes, the military, etc. Medical Internet of Things (MIoT), or the use of IoT in healthcare, is becoming a booming trend towards improving the health and wellbeing of billions of people by offering smooth and seamless medical facilities and by enhancing the services provided by medical practitioners, nurses, pharmaceutical companies, and other related government and non-government organizations. In recent times, this MIoT has gained higher attention for its potential to alleviate the massive burden on global healthcare, which has been caused by the rise of chronic diseases, the aging population, and emergency situations such as the recent COVID-19 global pandemic, where many government and non-government medical resources were challenged, owing to the rising demand for medical resources. It is evident that with this recent growing demand for MIoT, the associated technologies and its interconnected, heterogeneous nature adds new concerns as it becomes accessible to confidential patient data, often without patient or the medical staff consciousness, as the security and privacy of MIoT devices and technologies are often overlooked and undermined by relevant stakeholders. Hence, the growing security breaches that target the MIoT in healthcare are making the security and privacy of Medical IoT a crucial topic that is worth scrutinizing. In this study, we examined the current state of security and privacy of the MIoT, which has become of utmost concern among many security experts and researchers due to its rapid demand in recent times. Nevertheless, pertaining to the current state of security and privacy, we also examine and discuss a number of attack use cases, countermeasures and solutions, recent challenges, and anticipated future directions where further attention is required through this study.

A black hole attack is a severe attack that can be easily employed against routing in mobile ad hoc networks. A black hole is a malicious node that falsely replies for any route requests without having active route to specified destination and drops all the receiving packets. If these malicious nodes work together as a group then the damage will be very serious. This type of attack is called cooperative black hole attack. In S. Ramaswamy et al. (2003), we proposed a solution to identifying and preventing the cooperative black hole attack. Our solution discovers the secure route between source and destination by identifying and isolating cooperative black hole nodes. In this paper, via simulation, we evaluate the proposed solution and compare it with other existing solutions in terms of throughput, packet loss percentage, average end-to-end delay and route request overhead. The experiments show that (1) the AODV greatly suffers from cooperative black holes in terms of throughput and packet losses, and (2) our solution proposed in S. Ramaswamy et al. (2003) presents good performance in terms of better throughput rate and minimum packet loss percentage over other solutions, and (3) our solution can accurately prevent the cooperative black hole attacks. The example findings are: (1) the proposed scheme presents 5 - 8% more communication overhead of route request; and (2) The secure route discovery delay slightly increases the packet loss percentage.

This paper proposes a multi-channel MAC scheme for Vehicular Ad Hoc Networks (VANETs), which dynamically adjusts the intervals of Control Channel (CCH) and Service Channels (SCHs). Markov modeling is conducted to optimize the intervals based on the traffic condition. The scheme also introduces a multi-channel coordination mechanism to provide the contention-free access in SCHs. Theoretical analysis and simulation results show that the proposed scheme is able to help IEEE 1690.4 MAC improve the saturation throughput of SCHs significantly, while maintaining the prioritized transmission of critical safety information on the CCH.

Communication messages in Vehicular Ad-hoc Networks (VANETs) can be used to track movement of vehicles. In this paper, we address the problem of movement tracking and enhance location privacy without affecting security and safety of vehicles. By considering unique characteristics of VANETs, we firstly propose a synchronized pseudonym changing protocol based on the concept of forming groups among neighboring vehicles. Secondly, we analytically evaluate the anonymity and unlinkability of the proposed protocol. Finally, we do a series of simulations to evaluate the performance of our protocol in real VANET environments such as Manhattan and Urban. Simulation results show that our protocol is feasible and produces excellent performances. The main advantages of our protocol compared with the existing approaches include: 1) it makes larger anonymity set and higher entropy; 2) it reduces the tracking probability; 3) it can be used in both safety and non-safety communications; and 4) Vehicles need not suspend regular communication for changing pseudonyms.

In this paper we investigate the accuracy of human perception of haptic force direction applied to the hand. Haptic interfaces are commonly used in many applications and understanding the limitations of human perception would facilitate the design of these interfaces and the associated applications. The literature contains work related to force perception; however, none of which address the issue of the accuracy of haptic force direction perception. We discuss the design and implementation of the experiment used to evaluate the accuracy. Also presented are results related to training effects, fatigue and accuracy across angular regions