CAUCHY: Jurnal Matematika Murni dan Aplikasi
Vol 11, No 2 (2026): CAUCHY: JURNAL MATEMATIKA MURNI DAN APLIKASI

Geometry-Based Differentially Private Synthetic Tabular Data Generation via K-Means Clustering with Bounded and Discrete Feature Constraints

Robby Robby (Center for Mathematics and Society, Faculty of Science, Parahyangan Catholic University, Bandung 40141, Indonesia)
Agus Sukmana (Center for Mathematics and Society, Faculty of Science, Parahyangan Catholic University, Bandung 40141, Indonesia)
Erwinna Chendra (Center for Mathematics and Society, Faculty of Science, Parahyangan Catholic University, Bandung 40141, Indonesia)



Article Info

Publish Date
30 Nov 2026

Abstract

Most clustering-based differentially private synthetic data generation methods assume unconstrained continuous feature spaces and offer no mechanism for hard feature bound enforcement or discrete-valued attribute handling, which limits their practical applicability to real-world tabular data where such constraints are common. This paper proposes a geometry-based mechanism that generates synthetic tabular data by application of Laplace noise jointly to K-means cluster centroids and within-cluster radial distances, calibrated via a data-dependent sensitivity approximation. Three components distinguish the approach from prior work: coordinate-wise centroid reflection to enforce hard feature bounds after perturbation, coordinate-wise clipping to enforce bounds on reconstructed synthetic points, and randomized rounding for discrete features as a post-processing step. A utility-driven calibration strategy selects the privacy budget to meet a user-specified target Adjusted Rand Index (ARI), which makes the privacyutility trade-off directly interpretable. Baseline comparisons on a two-dimensional illustrative example show that the proposed mechanism achieves ARI=0.666 at 1.60, which substantially outperforms direct coordinate-wise noise addition at the same budget (ARI=0.199), while it matches the non-private synthesis baseline (ARI=0.624). Across 30 independent runs the mechanism achieves mean ARI=0.6290.108, which confirms that the calibration target is reliably met under stochastic variation.

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Journal Info

Abbrev

Math

Publisher

Subject

Mathematics

Description

Jurnal CAUCHY secara berkala terbit dua (2) kali dalam setahun. Redaksi menerima tulisan ilmiah hasil penelitian, kajian kepustakaan, analisis dan pemecahan permasalahan di bidang Matematika (Aljabar, Analisis, Statistika, Komputasi, dan Terapan). Naskah yang diterima akan dikilas (review) oleh ...