Blink: Link Local Differential Privacy in Graph Neural Networks via Bayesian Estimation

التفاصيل البيبلوغرافية
العنوان: Blink: Link Local Differential Privacy in Graph Neural Networks via Bayesian Estimation
المؤلفون: Zhu, Xiaochen, Tan, Vincent Y. F., Xiao, Xiaokui
سنة النشر: 2023
المجموعة: Computer Science
مصطلحات موضوعية: Computer Science - Machine Learning, Computer Science - Cryptography and Security
الوصف: Graph neural networks (GNNs) have gained an increasing amount of popularity due to their superior capability in learning node embeddings for various graph inference tasks, but training them can raise privacy concerns. To address this, we propose using link local differential privacy over decentralized nodes, enabling collaboration with an untrusted server to train GNNs without revealing the existence of any link. Our approach spends the privacy budget separately on links and degrees of the graph for the server to better denoise the graph topology using Bayesian estimation, alleviating the negative impact of LDP on the accuracy of the trained GNNs. We bound the mean absolute error of the inferred link probabilities against the ground truth graph topology. We then propose two variants of our LDP mechanism complementing each other in different privacy settings, one of which estimates fewer links under lower privacy budgets to avoid false positive link estimates when the uncertainty is high, while the other utilizes more information and performs better given relatively higher privacy budgets. Furthermore, we propose a hybrid variant that combines both strategies and is able to perform better across different privacy budgets. Extensive experiments show that our approach outperforms existing methods in terms of accuracy under varying privacy budgets.
Comment: 17 pages, accepted by ACM CCS 2023 as a conference paper
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2309.03190
رقم الأكسشن: edsarx.2309.03190
قاعدة البيانات: arXiv