Parameter Privacy-Preserving Data Sharing: A Particle-Belief MDP Formulation
Haokun Yu, Jingyuan Zhou, Kaidi Yang
TL;DR
This work addresses parameter privacy in data sharing for continuous-state dynamical systems by formulating a privacy-utility trade-off using the leakage $I^{\boldsymbol{\pi}}(\Theta; Y_{1:T},W_{1:T})$ and a distortion constraint. It develops a belief-MDP framework and introduces a scalable particle-belief MDP via Sequential Monte Carlo, paired with a regime-adaptive Gaussian-mixture upper bound on mutual information to enable tractable optimization. A practical RL-based solver combining an MGF encoder and a DDPG learner optimizes continuous data-sharing policies. Empirical results on a mixed-autonomy platoon show that the learned policy significantly hinders inference of human-driving parameters while preserving data usability and system performance, highlighting the approach’s real-world applicability for privacy-preserving data sharing in networked control systems.
Abstract
This paper investigates parameter-privacy-preserving data sharing in continuous-state dynamical systems, where a data owner designs a data-sharing policy to support downstream estimation and control while preventing adversarial inference of a sensitive parameter. This data-sharing problem is formulated as an optimization problem that trades off privacy leakage and the impact of data sharing on the data owner's utility, subject to a data-usability constraint. We show that this problem admits an equivalent belief Markov decision process (MDP) formulation, which provides a simplified representation of the optimal policy. To efficiently characterize information-theoretic privacy leakage in continuous state and action spaces, we propose a particle-belief MDP formulation that tracks the parameter posterior via sequential Monte Carlo, yielding a tractable belief-state approximation that converges asymptotically as the number of particles increases. We further derive a tractable closed-form upper bound on particle-based MI via Gaussian mixture approximations, which enables efficient optimization of the particle-belief MDP. Experiments on a mixed-autonomy platoon show that the learned continuous policy substantially impedes inference attacks on human-driving behavior parameters while maintaining data usability and system performance.
