2025_programme: Robust channel comparison metrics for underwater physical layer authentication

• Day: June 19, Thursday
    Location / Time: D. CHLOE at 14:30-14:50
• Last minutes changes: N/A
• Session: 21. Underwater Communications and Networking
  Organiser(s): Charalampos Tsimenidis, Paul Mitchell, Konstantinos Pelekanakis
  Chairperson(s): Charalampos Tsimenidis, Paul Mitchell, Konstantinos Pelekanakis
• Lecture: Robust channel comparison metrics for underwater physical layer authentication [Invited]
  Paper ID: 2226
  Author(s): Davide Eccher, Paolo Casari
  Presenter: Davide Eccher
  Abstract: The physical layer security (PLS) framework enables authentication and privacy in communication systems. For this, it leverages unique channel features that can be reliably observed by legitimate parties (Alice and Bob) while being mostly secret to attackers (Eve). In underwater acoustic networks, the minimal correlation of acoustic channels in space provides a promising context for PLS.\n\nOur research focuses on implementing authentication via PLS using channel crafting. More specifically, we craft an artificial channel starting from a secret seed, and then apply this channel to the outgoing signal. We use the parameters of the channel impulse response (CIR), namely the delay and amplitude of each arrival, as the secret shared seed on which we base the crafting process. The receiver performs the authentication by comparing the CIR extracted from the incoming signal with an expected CIR. \nTherefore, we need a distance metric that measures the superimposability of two channels, indicating that such channels have been generated by the two ends of the same link. Based on this metric, a decision algorithm can perform authentication.\n\nIn this paper, we present the implementation of four algorithms to compute a distance measure between two CIRs. The algorithms take into account that the CIRs are not perfectly reciprocal. Differences can originate from measurement errors, node movement, noise, or other physical phenomena, so that the delay and amplitude values of the arrivals fluctuate, even to the point of disappearing. \nSuch differences may lead to increased false alarms and missed detections, and therefore a convenient CIR distance metric should be robust against them. Specifically, we propose to reward strong channel similarities more than we penalize large differences.\n\nWe present some performance results and comparisons among the proposed metrics, where we compute acoustic channels via Bellhop's ray model in order to achieve realistic authentication simulations.
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  This paper is a candidate for the "Prof. Leif Bjørnø Best Student Paper Award (for students under 35)"
• Corresponding author: Mr Davide Eccher
  Affiliation: University of Trento
  Country: Italy