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- Gisdakis, Stylianos
(författare)
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Secure and Privacy Preserving Urban Sensing Systems
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The emergence of resource-rich mobile devices and smart vehicles has paved the way for Urban Sensing. In this new paradigm, users sense their environment and become part of an unprecedented large-scale network of sensors, with extensive spatial and temporal coverage, that enables the collection and dissemination of real-time information, practically, from anywhere. Urban sensing can facilitate the deployment of innovative applications that can address the ever-growing concerns for citizens’ well-being. Nevertheless, the openness of such systems (ideally anyone can participate) and the richness of the data users contribute unavoidably raise significant concerns for both the security of urban sensing applications and the privacy of the participating users. In this thesis we consider different urban sensing application domains: vehicular communication networks, intelligent transportation systems and environmental monitoring applications. We begin with a detailed analysis of the security and privacy requirements of these applications domains. Our objective is to protect users from the system (by ensuring their anonymity and privacy) and urban sensing systems from malicious users (by holding malicious users accountable of their actions). This is not straight-forward; anonymity may tempt malicious user behavior, compromising the reliability of the entire urban sensing system.Towards that, we design and implement secure and privacy-preserving identity management systems that can accommodate these requirements. We demonstrate their efficiency, practicality, and scalability through extensive experimental evaluations. Furthermore, we formally evaluate formally their security and privacy preserving properties.
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| 2. |
- Hewage, Kasun
(författare)
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Towards Secure Synchronous Communication Architectures for Wireless Networks
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The vision behind the Internet of Things (IoT) revolves around creating a connected ecosystem where devices, people, and systems collaborate seamlessly, unlocking new possibilities, improving efficiency, and enhancing our daily lives. IoT encloses many device classes, including low-power wireless devices that rely on batteries or energy harvesting. Due to the low-power nature and the instability of the wireless links, networks comprising these IoT devices are commonly known as Low-power and Lossy Networks (LLNs).Several network-wide flooding-based communication primitives that employ synchronous transmissions have emerged as an alternative to traditional multi-hop routing, thereby creating a new dimension of LLN research. While these primitives have demonstrated superior performance in terms of latency and reliability, they have received little attention regarding network security. In this dissertation, we study the effectiveness of several attacks that strive to disrupt synchronous transmission-based protocols. Based on the findings from this work, we examine the security requirements and propose encryption and lightweight flood verification methods to protect synchronous transmission-based flooding protocols from these attacks.Realising the IoT's vision demands employing well-established communication technologies like the Internet Protocol (IP) suite protocols to ensure interoperability. However, the IP suite protocols are not explicitly designed for low-power networks; hence using them in LLNs encounters numerous challenges. Some of my work included in this dissertation focuses on the performance issues of two widely used IP suite protocols: Transmission Control Protocol (TCP) and Datagram Transport Layer Security (DTLS). We propose to replace the conventional link layer protocols of the LLN stacks with a synchronous transmission-based protocol to enhance the reliability that TCP expects in lower layers, thereby improving the TCP performance. We introduce novel header compression mechanisms to reduce the size of DTLS messages without violating end-to-end security. Reducing the size of DTLS messages lowers the transmission overhead, improving its performance in LLNs.Optical Wireless Communication (OWC) is a complementary technology to radio frequency communication. Specifically, visible light communication (VLC) has proven its capability to offer higher data transfer rates, enabling faster and more efficient communication. The last work of this dissertation draws inspiration from synchronous transmissions in LLNs and presents an OWC-based time synchronisation system for high-speed VLC access points to synchronise their transmissions. This time synchronisation system has a considerably lower synchronisation jitter than the widely-used Precision Time Protocol (PTP).
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