Biblio

As IoT technologies mature, they are increasingly finding their way into more sensitive domains, such as Medical and Industrial IoT, in which safety and cyber-security are paramount. While the number of deployed IoT devices continues to increase annually, they still present severe cyber-security vulnerabilities, turning them into potential targets and entry points to support further attacks. Naturally, as these nodes are compromised, attackers aim at setting up stealthy communication behaviours, to exfiltrate data or to orchestrate nodes of a botnet in a cloaked fashion. Network covert channels are increasingly being used with such malicious intents. The IEEE 802.15.4 is one of the most pervasive protocols in IoT, and a fundamental part of many communication infrastructures. Despite this fact, the possibility of setting up such covert communication techniques on this medium has received very little attention. We aim at analysing the performance and feasibility of such covert-channel implementations upon the IEEE 802.15.4 protocol. This will enable a better understanding of the involved risk and help supporting the development of further cyber-security mechanisms to mitigate this threat.

Consensus is a basic building block in distributed systems for a myriad of related problems that involve agreement. For asynchronous networks, consensus has been proven impossible, and is well known as Augean task. Failure Detectors (FDs) have since emerged as a possible remedy, able to solve consensus in asynchronous systems under certain assumptions. With the increasing use of asynchronous, wireless Internet of Things (IoT) technologies, such as IEEE 802.15.4/6LoWPAN, the demand of applications that require some form of reliability and agreement is on the rise. What was missing so far is an FD that can operate under the tight constraints offered by Low Power and Lossy Networks (LLNs) without compromising the efficiency of the network. We present 6LoFD, an FD specifically aimed at energy and memory efficient operation in small scale, unreliable networks, and evaluate its working principles by using an ns-3 implementation of 6LoFD.

This work analyzed the coding gain that is provided in 6LoWPAN transceivers when channel-coding methods are used. There were made improvements at physical layer of 6LoWPAN technology in the system suggested. Performance analysis was performed using turbo, LDPC and convolutional codes on IEEE 802.15.4 standard that is used in the relevant physical layer. Code rate of convolutional and turbo codes are set to 1/3 and 1/4. For LDPC codes, the code rate is set as 3/4 and 5/6. According to simulation results obtained from the MATLAB environment, turbo codes give better results than LDPC and convolutional codes. It is seen that an average of 3 dB to 8 dB gain is achieved in turbo codes, in LDPC and convolutional coding, it is observed that the gain is between 2 dB and 6 dB depending on the modulation type and code rate.

Reliable group communication is an important cornerstone for various applications in the domain of Industrial Internet of Things (IIoT). Yet, despite various proposals, state-of- the-art (open) protocol stacks for IPv6-enabled Low Power and Lossy Networks (LLNs) have little to offer, regarding standardized or agreed-upon protocols for correct multicast routing, not to mention reliable multicast. We present an informal computational model, which allows us to analyze the respective candidates for multicast routing. Further, we focus on the IEEE 802.15.4/6LoWPAN stack and discuss prominent multicast routing protocols and how they fit into this model.

Low-power wireless networks provide IPv6 connectivity through 6LoWPAN, a set of standards to aggressively compress IPv6 packets over small maximum transfer unit (MTU) links such as 802.15.4.The entire purpose of IP was to interconnect different networks, but we find that different 6LoWPAN implementations fail to reliably communicate with one another. These failures are due to stacks implementing different subsets of the standard out of concern for code size. We argue that this failure stems from 6LoWPAN's design, not implementation, and is due to applying traditional Internet protocol design principles to low- power networks.We propose three design principles for Internet protocols on low-power networks, designed to prevent similar failures in the future. These principles are based around the importance of providing flexible tradeoffs between code size and energy efficiency. We apply these principles to 6LoWPAN and show that the modified protocol provides a wide range of implementation strategies while allowing implementations with different strategies to reliably communicate.

The Industrial Internet of Things (IIoT) paradigm represents nowadays the cornerstone of the industrial automation since it has introduced new features and services for different environments and has granted the connection of industrial machine sensors and actuators both to local processing and to the Internet. One of the most advanced network protocol stack for IoT-IIoT networks that have been developed is 6LoWPAN which supports IPv6 on top of Low-power Wireless Personal Area Networks (LoWPANs). 6LoWPAN is usually coupled with the IEEE 802.15.4 low-bitrate and low-energy MAC protocol that relies on the time-slotted channel hopping (TSCH) technique. In TSCH networks, a coordinator node synchronizes all end-devices and specifies whether (and when) they can transmit or not in order to improve their energy efficiency. In this scenario, the scheduling strategy adopted by the coordinator plays a crucial role that impacts dramatically on the network performance. In this paper, we present a novel scheduling strategy for time-slot allocation in IIoT communications which aims at the improvement of the overall network fairness. The proposed strategy mimics the well-known shell game turning the totally unfair mechanics of this game into a fair scheduling strategy. We compare our proposal with three allocation strategies, and we evaluate the fairness of each scheduler showing that our allocator outperforms the others.

More and more industrial devices are expected to connect to the internet seamlessly. IPv6-based industrial wireless network can solve the address resources limitation problem. It is a challenge about how to ensure the wireless node join security after introducing the IPv6. In this paper, we propose a multiple nodes join mechanism, which includes a timeslot allocation method and secure join process for the IPv6 over IEEE 802.15.4e network. The timeslot allocation method is designed in order to configure communication resources in the join process for the new nodes. The test platform is implemented to verify the feasibility of the mechanism. The result shows that the proposed mechanism can reduce the communication cost for multiple nodes join process and improve the efficiency.

Smart Grid is a major element of the Smart City concept that enables two-way communication of energy data between electric utilities and their consumers. These communication technologies are going through sharp modernization to meet future demand growth and to achieve reliability, security, and efficiency of the electric grid. In this paper, we implement an IPv6 based two-way communication system between the transformer agent (TA), installed at local electric transformer and various customer agents (CAs), connected to customer's smart meter. Various homes share their energy usage with the TA which in turn sends the utility's recommendations to the CAs. Raspberry Pi is used as hardware for all the CAs and the TA. We implement a self-healing mesh network between all nodes using OpenLab IEEE 802.15.4 chips and Routing Protocol for Low-Power and Lossy Networks (RPL), and the data is secured by RSA/AES keys. Several tests have been conducted in real environments, inside and outside of Carleton University, to test the performance of this communication network in various obstacle settings. In this paper, we highlight the details behind the implementation of this IPv6-based smart grid communication system, the related challenges, and the proposed solutions.

We argue on the need for a dedicated medium access control (MAC) for Vehicular VLC (V-VLC). The huge unlicensed spectrum that can support high throughput applications and the intrinsic security due to the LOS requirement make visible light a viable candidate for use in vehicular communications. In some first research work, the directionality of V-VLC has been considered and an initial conclusion was that the small collision domain leads to negligible interference and, thus, dedicated mechanisms for medium access are unnecessary. However, in a more realistic simulation setup using the Luxembourg mobility model, we are able to show that, in certain geographical areas, the number of transmitters seen at a single receiver can easily grow up to 30. Considering packet transmissions, the interference-induced packet loss can be substantial, reaching up to 13 % during rush hours. We thus make the case that this packet loss should be mitigated with a dedicated MAC for coordinated access control in V-VLC.

The Internet of Things leads to the inter-connectivity of a wide range of devices. This heterogeneity of hardware and software poses significant challenges to security. Constrained IoT devices often do not have enough resources to carry the overhead of an intrusion protection system or complex security protocols. A typical initial step in network security is a network scan in order to find vulnerable nodes. In the context of IoT, the initiator of the scan can be particularly interested in finding constrained devices, assuming that they are easier targets. In IoT networks hosting devices of various types, performing a scan with a high discovery rate can be a challenging task, since low-power networks such as IEEE 802.15.4 are easily overloaded. In this paper, we propose an approach to increase the efficiency of network scans by combining them with active network measurements. The measurements allow the scanner to differentiate IoT nodes by the used network technology. We show that the knowledge gained from this differentiation can be used to control the scan strategy in order to reduce probe losses.

This paper addresses the need for standard communication protocols for IoT devices with limited power and computational capabilities. The world is rapidly changing with the proliferation and deployment of IoT devices. This will bring in new communication challenges as these devices are connected to Internet and need to communicate with each other in real time. The paper provides an overview of IoT system architecture and the forthcoming challenges it will bring. There is an urging need to establish standards for communication in the IoT world. With the recent development of new protocols like CoAP, 6LowPAN, IEEE 802.15.4 and Thread in different layers of OSI model, additional challenges also present themselves. Performance and data management is becoming more critical than ever before due to the complexity of connecting raging number of IoT devices. The performance of the systems dealing with IoT devices will require appropriate capacity planning the associated development of data centers. Finally, the paper also presents some reasonable approaches to address the above issues in the IoT world.

Tactical wireless sensor networks (WSNs) are deployed over a region of interest for mission centric operations. The sink node in a tactical WSN is the aggregation point of data processing. Due to its essential role in the network, the sink node is a high priority target for an attacker who wishes to disable a tactical WSN. This paper focuses on the mitigation of sink-node vulnerability in a tactical WSN. Specifically, we study the issue of protecting the sink node through a technique known as k-anonymity. To achieve k-anonymity, we use a specific routing protocol designed to work within the constraints of WSN communication protocols, specifically IEEE 802.15.4. We use and modify the Lightweight Ad hoc On-Demand Next Generation (LOADng) reactive-routing protocol to achieve anonymity. This modified LOADng protocol prevents an attacker from identifying the sink node without adding significant complexity to the regular sensor nodes. We simulate the modified LOADng protocol using a custom-designed simulator in MATLAB. We demonstrate the effectiveness of our protocol and also show some of the performance tradeoffs that come with this method.

As Internet of things (IoT) continue to ensconce into our homes, offices, hospitals, electricity grids and other walks of life, the stakes are too high to leave security to chance. IoT devices are resource constrained devices and hence it is very easy to exhaust them of their resources or deny availability. One of the most prominent attacks on the availability is the Distributed Denial of service (DDoS) attack. Although, DDoS is not a new Internet attack but a large number of new, constrained and globally accessible IoT devices have escalated the attack surface beyond imagination. This paper provides a broad anatomy of IoT protocols and their inherent weaknesses that can enable attackers to launch successful DDoS attacks. One of the major contributions of this paper is the implementation and demonstration of UDP (User Datagram Protocol) flood attack in the Contiki operating system, an open-source operating system for the IoT. This attack has been implemented and demonstrated in Cooja simulator, an inherent feature of the Contiki operating system. Furthermore, in this paper, a rate limiting mechanism is proposed that must be incorporated in the Contiki OS to mitigate UDP flood attacks. This proposed scheme reduces CPU power consumption of the victim by 9% and saves the total transmission power of the victim by 55%.