Embedded devices in various forms are increasingly becoming part of everyday life, constituting the Internet of Things(IoT). As IoT applications are beginning to gather and process critical data, the rising importance of the security of such networks is evident. In the basis of IoT lie Machine-to-Machine (M2M) networks which provide the necessary communication infrastructure between heterogeneous, resource-constrained devices. In such devices, Physical Unclonable Functions(PUFs) provide a cost-efficient and highly secure way to enhance many security aspects of embedded devices, including uniquely identifying a device, generating and storing cryptography keys and secure storage.
The main aim of this project is to develop methods and perform case studies for using PUFs in IoT scenarios and enhancing device identification, secure enrolment and other security functions while requiring minimal configuration which can be provided out-of-box by the manufacturer. The development of a demonstrator application, complete with the necessary software and hardware, will also be undertaken in order to definitively establish the validity of the proposed solutions.
Physical Unclonable Functions(PUFs) are a novel concept of generating unique identifiers based on physical properties of electronic devices. By unquestionably identifying not only a specific device family but also a certain instance of that device, it is possible to create methods of verifying the source of data without necessarily exposing the person who created it. The relevance of such methods is rapidly increasing due to the growth of ubiquitous networked devices. This work describes a signature protocol incorporating the potential of the PUFs to sign pieces of data and verify their authenticity when required. Through the demonstration of an operational prototype system, the challenges and capabilities of such architectures were explored and discussed.
Wireless Sensor Networks (WSN) are typically consisted of hundreds of nodes which generate a high volume of network traffic. Due to the multi-hop communication architecture often used in such networks, bottlenecks are bound to appear in parts of the system. These bottlenecks, also referred to as network congestion, can have a vast effect on network performance and, given the constricted resources of WSNs nodes, result in the system failing to serve its purpose. Special care should be taken to avoid or alleviate the problem of congestion, by developing specific algorithms and methods. Our study aimed to lessen the effect of congestion in WSNs by studying, implementing and evaluating techniques of congestion avoidance.
In the context of this study, we designed and implemented an innovative congestion avoidance method which can successfully handle three different packet priorities, under the name Priority Based Congestion Avoidance Technique (PB-CAT). PB-CAT uses a mechanism of packet delay and merging in order to reduce the total transmissions and increase the optimal use of the communication medium, resulting in improved network performance.
In order to evaluate our method, we implemented it using the Contiki OS and performed extensive simulations in the Cooja network simulator. The simulation results presented a clear improvement of the network metrics, particularly in sensor networks with a high volume of traffic, where we observed a considerable amount of enhancement in the quality of the network operation.