Authorization or access control limits the actions a user may perform on a computer system, based on predetermined access control policies, thus preventing access by illegitimate actors. Access control for the Internet of Things (IoT) should be tailored to take inherent IoT network scale and device resource constraints into consideration. However, common authorization systems in IoT employ conventional schemes, which suffer from overheads and centralization. Recent research trends suggest that blockchain has the potential to tackle the issues of access control in IoT. However, proposed solutions overlook the importance of building dynamic and flexible access control mechanisms. In this paper, we design a decentralized attribute-based access control mechanism with an auxiliary Trust and Reputation System (TRS) for IoT authorization. Our system progressively quantifies the trust and reputation scores of each node in the network and incorporates the scores into the access control mechanism to achieve dynamic and flexible access control. We design our system to run on a public blockchain, but we separate the storage of sensitive information, such as user’s attributes, to private sidechains for privacy preservation. We implement our solution in a public Rinkeby Ethereum test-network interconnected with a lab-scale testbed. Our evaluations consider various performance metrics to highlight the applicability of our solution for IoT contexts.

Within the Internet of Things (IoT) and blockchain research, there is a growing interest in decentralizing health monitoring systems, to provide improved privacy to patients, without relying on trusted third parties for handling patients’ sensitive health data. With public blockchain deployments being severely limited in their scalability, and inherently having latency in transaction processing, there is room for researching and developing new techniques to leverage the security features of blockchains within healthcare applications. This paper presents a solution for patients to share their biomedical data with their doctors without their data being handled by trusted third party entities. The solution is built on the Ethereum blockchain as a medium for negotiating and record-keeping, along with Tor for delivering data from patients to doctors. To highlight the applicability of the solution in various health monitoring scenarios, we have considered three use-cases, namely cardiac monitoring, sleep apnoea testing, and EEG following epileptic seizures. Following the discussion about the use cases, the paper outlines a security analysis performed on the proposed solution, based on multiple attack scenarios. Finally, the paper presents and discusses a performance evaluation in terms of data delivery time in comparison to existing centralized and decentralized solutions.

Modern Smart Buildings will utilize sensor technologies to obtain current information of the occupants and use it to provide automatic services to improve the safety, efficient use, productivity, and comfort. Energy saving is one of the promises of Smart Buildings. This can be achieved by controlling the HVAC system, lights, and other energy consuming appliances in relation to the activities of people in the building. In particular, presence is an important factor to consider. By using beacons such as those based on Bluetooth Low Energy (BLE) and mobile phones, one can deduct occupancy information by interacting, over WiFi, with a central server. In the present study, we investigate BLE utilization for transmitting the occupancy data to the server using off-the-self devices with several parameters, e.g., distance, packet size, and line-of-sight state. Furthermore, we propose a utilization of size-constrained BLE packets for transmitting occupancy data, which was previously only possible by means of HTTP over WiFi. The result shows that it is possible to transmit occupancy data via BLE, despite of its resource constraints. Bluetooth is also shown to be about 30% more energy efficient than WiFi to perform occupancy data transmission, i.e., the mobile phone has 16 hours and 38 minutes of battery life when running on BLE communication scheme and 14 hours and 46 minutes in WiFi communication.

Wireless Sensor Network (WSN) usage for buildings and household has been increasingly popular because it offers various benefits, such as home automation and home surveillance. Therefore, in order to increase WSN usage flexibility, remote controlling which enables remote administration is required. In fact, generally WSN is controlled by a coordinator (sink node) that is located closely to the WSN area itself. By utilizing iterative development, which is suitable for main and supporting application development with several iterations, this research proposes WSN and Internet Protocol (IP) interoperability that enables remote controlling and managing through Internet. Eventually, this research creates a web-based application which will be implemented to a wireless Access Point (AP) for easier WSN remote controlling. Furthermore, it could accommodate WSN from various vendors by software only solution.

Blockchain offers several technological breakthroughs, ranging from monetary solutions to healthcare systems. Some approaches have proposed blockchain implementation in IoT for providing better performance and scalability. However, massive scale implementation of IoT devices suffers from several issues in identity and access managements of interconnected devices. The present study proposes the combination of permissioned blockchain and Keyless Signature Infrastructure (KSI) as a means of governing the identity and access management of IoT devices. KSI is known for its ability to offer digital signature services without the need of public or private key but hash trees updated in a regular basis. With the decentralization fashion of blockchain, KSI can be implemented more efficiently. The results may give an identity and access management with high scalability.