Security and accuracy tradeoffs in remote monitoring with eavesdroppers
Legitimate Reconstruction Advantage in Wiretapped Semantics-Aware Remote Monitoring
Information Theory
Summary
When remote systems send updates about a process, both the intended receiver and a spy eavesdropping may hear those updates. The authors study how to make sure the intended receiver can accurately understand the system’s current state while the spy gets it wrong. They analyze how often and how reliably this advantage happens, finding surprising situations where sending updates more often or improving the main receiver’s channel can actually help the spy too. They also show how this understanding can guide where to place security zones to keep eavesdroppers away.
What this means in practice
- •For network schedulers: Design transmission schedules that optimize legitimate receiver accuracy while limiting eavesdropper reconstruction in remote monitoring systems.
- •For security engineers: Implement geofencing constraints to spatially restrict eavesdropper effectiveness based on monitoring system communication patterns.
Authors
Bowen Li, Nikolaos Pappas
Abstract
This paper investigates joint accuracy and security in semantics-aware remote monitoring, where source updates intended for a legitimate receiver may also be intercepted by an eavesdropper. We define legitimate reconstruction advantage (LRA) as the joint event that the intended receiver correctly reconstructs the current source state using received updates while the eavesdropper reconstructs it incorrectly. Source evolution changes the relevance of received updates at the two receivers, so their marginal reconstruction accuracies do not, in general, determine the probability of this joint event. Under randomized stationary (RS) transmission and zero-order-hold reconstruction at both receivers, we derive an explicit joint stationary distribution and closed-form expressions for LRA probability and persistence for general finite-state ergodic Markov sources. For two-state and uniform-transition sources, we obtain algebraic expressions that enable low-complexity optimization of RS policies. Analytical and numerical results show that maximizing the probability of legitimate advantage need not maximize its persistence. For two-state sources, rare-transmission analysis reveals that, at a fixed sum of transition probabilities, greater transition asymmetry can increase persistence while reducing LRA probability. Moreover, optimizing marginal accuracy and security metrics can select policies that are suboptimal for LRA. Counterintuitively, more frequent transmission or improved legitimate-channel reliability can increase legitimate reconstruction accuracy while reducing LRA probability. Finally, a geofencing application translates prescribed LRA requirements into spatial constraints on eavesdropper locations.