Scalable and Secure Multicast Routing for Mobile Ad-hoc Networks

Mobile Ad-Hoc Networks (MANETs) are decentralized and autonomous communication systems: They can be used to provide connectivity when a natural disaster has brought down the infrastructure, or they can support freedom of speech in countries with governmental Internet restrictions. MANET design requires careful attention to scalability and security due to low-capacity and error-prone wireless links as well as the openness of these systems. In this thesis, we address the issue of multicast as a means to efficiently support the MANET application of group communication on the network layer. To this aim, we first survey the research literature on the current state of the art in MANET routing, and we identify a gap between scalability and security in multicast routing protocols–two aspects that were only considered in isolation until now. We then develop an explicit multicast protocol based on the design of a secure unicast protocol, aiming to maintain its security properties while introducing minimal overhead. Our simulation results reveal that our protocol reduces bandwidth utilization in group communication scenarios by up to 45 % compared to the original unicast protocol, while providing significantly better resilience under blackhole attacks. A comparison with pure flooding allows us to identify a practical group size limit, and we present ideas for better large-group support

Reverse Engineering Human Mobility in Large-scale Natural Disasters

Delay/Disruption-Tolerant Networks (DTNs) have been around for more than a decade and have especially been proposed to be used in scenarios where communication infrastructure is unavailable. In such scenarios, DTNs can offer a best-effort communication service by exploiting user mobility. Natural disasters are an important application scenario for DTNs when the cellular network is destroyed by natural forces. To assess the performance of such networks before deployment, we require appropriate knowledge of human mobility. In this paper, we address this problem by designing, implementing, and evaluating a novel mobility model for large-scale natural disasters. Due to the lack of GPS traces, we reverse-engineer human mobility of past natural disasters (focusing on 2010 Haiti earthquake and 2013 Typhoon Haiyan) by leveraging knowledge of 126 experts from 71 Disaster Response Organizations (DROs). By means of simulation-based experiments, we compare and contrast our mobility model to other well-known models, and evaluate their impact on DTN performance. Finally, we make our source code available to the public

Xcastor: Secure and scalable group communication in ad hoc networks

Mobile ad hoc networks (MANETs) are emerging as a practical technology for emergency response communication in the case a centralized infrastructure malfunctions or is not available. Using smartphones as communication devices, MANETs may be readily established among the civilian population of affected areas. Beneficiaries would be civilian first responders, which may form small collaborating groups. Communication in such groups must be reliable for disaster response to be effective. In this paper, we address the issue of reliable group communication on the network layer. We design and implement the first secure explicit multicast routing protocol called Xcastor, in which we extend the secure and scalable routing concept of the Castor unicast routing protocol towards supporting reliable communication for large numbers of small groups. By simulation, we show significant performance improvements over Castor

Xcastor: Secure and Scalable Group Communication in Ad Hoc Networks

Mobile ad hoc networks (MANETs) are emerging as a practical technology for emergency response communication in the case a centralized infrastructure malfunctions or is not available. Using smartphones as communication devices, MANETs may be readily established among the civilian population of affected areas. Beneficiaries would be civilian first responders, which may form small collaborating groups. Communication in such groups must be reliable for disaster response to be effective. In this paper, we address the issue of reliable group communication on the network layer. We design and implement the first secure explicit multicast routing protocol called Xcastor, in which we extend the secure and scalable routing concept of the Castor unicast routing protocol towards supporting reliable communication for large numbers of small groups. By simulation, we show significant performance improvements over Castor

SEMUD: Secure multi-hop device-to-device communication for 5G public safety networks

Multi-hop Device-to-Device (D2D) communication has emerged as a key enabler for public safety applications in 5G networks. A failure of these applications would be catastrophic since they control vital human-in-the-loop services. As a result, it is of utmost importance to identify and mitigate security risks prior to commercial deployment. To this end, we devise SEMUD, the first secure multi-hop D2D solution for 5G mobile networks. It enables robust and secure communication even in the absence of supporting infrastructure. We design SEMUD to be compliant with 3GPP Proximity-based Services, the standard to implement D2D communications. We implement SEMUD in the ns-3 simulator and our testbed. Via extensive simulation, we assert its resilience against strong adversaries and attacks. Furthermore, we show the energy efficiency and achievable throughput of our proposal on real devices