Anonymity of the Base-Station in Wireless Sensor Networks

Author/Creator

Author/Creator ORCID

Date

2022-01-01

Department

Computer Science and Electrical Engineering

Program

Engineering, Computer

Citation of Original Publication

Rights

Distribution Rights granted to UMBC by the author with a 1 year embargo. Access will being on Nov. 29, 2023.
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Abstract

In a wireless sensor network (WSN), nodes probe their surroundings and send their measurements over multi-hop routes to an in-situ base-station (BS). The BS aggregates the collected data and orchestrates a response either autonomously or through consultation with a command center. Since the BS is crucial to the WSN operation, an adversary might target it to inflict the most damage to the network. Even if the BS is camouflaged, an adversary may locate it by intercepting transmissions and applying traffic analysis. This dissertations opts to increase the anonymity of the BS and conceal its location. Two adversary models are considered, local and global. The former sniffs packet transmission and measures transmission volume given that the BS vicinity often experiences the most packet relaying activities. To counter such a local sniffer, a mechanism is proposed that generates bogus traffic to confound high transmissions volume away from the BS to mislead the adversary. Meanwhile, a global adversary intercepts all transmissions and uses sophisticated traffic analysis models such as Evidence Theory (ET). Using ET, the adversary correlates intercepted transmissions to deduce new evidence of data routes that end at the BS. First, we exploit the complexity of ET as a countermeasure by dynamically increasing the transmission range of nodes to cover more destinations. Second, we manipulate the ET analysis via fake traffic generation in low activity areas to diminish the importance of regions closer to the BS. Scarcity of energy resources is often overlooked in favor of boosting network anonymity. In this dissertations, by analyzing energy consumption patterns, we first propose a novel energy-aware and multi-zone scheme to significantly reduce the overhead of countermeasures on highly overburdened nodes in the BS proximity, and hence significantly improve the WSN lifespan. Then, the multi-zone design is extended by a novel cross-layer technique that exploits transmission range adjustment to confuse the adversary about the data paths. This results in a versatile and effective countermeasure that significantly improves anonymity of the BS without negative implications on the network lifespan. ET only uses spatial aspects of intercepted transmissions; hence we propose an enhanced version of ET (EET) that also utilizes temporal correlation of transmissions to draw further insight about the network. Two countermeasures, namely, Delaying Packets Relaying (DPR) and Assisted Deception (AD), are developed to make the WSN resilient to both ET and EET. DPR imposes buffering delay at each node while AD allows nodes to coordinate and inject timed deceptive packets. Both techniques aim to disturb the time correlation of consecutive transmissions that EET relies on. The attack and countermeasures are validated through simulation experiments.