Device-centric Federated Analytics At Ease

TL;DR

Deck is a device-centric federated analytics system enabling direct, privacy-preserving data queries on mobile devices, significantly reducing query delay and supporting large-scale deployment.

Contribution

The paper introduces Deck, a novel system for flexible, device-centric federated analytics that bypasses app developers and ensures privacy through innovative techniques.

Findings

Reduces query delay by up to 30x in real-world deployment.

Supports analysis on 20 popular Android apps with negligible overhead.

Successfully deployed on 1,642 volunteers, demonstrating scalability.

Abstract

Nowadays, high-volume and privacy-sensitive data are generated by mobile devices, which are better to be preserved on devices and queried on demand. However, data analysts still lack a uniform way to harness such distributed on-device data. In this paper, we propose a data querying system, Deck, that enables flexible device-centric federated analytics. The key idea of Deck is to bypass the app developers but allow the data analysts to directly submit their analytics code to run on devices, through a centralized query coordinator service. Deck provides a list of standard APIs to data analysts and handles most of the device-specific tasks underneath. Deck further incorporates two key techniques: (i) a hybrid permission checking mechanism and mandatory cross-device aggregation to ensure data privacy; (ii) a zero-knowledge statistical model that judiciously trades off query delay and query resource expenditure on devices. We fully implement Deck and plug it into 20 popular Android apps. An in-the-wild deployment on 1,642 volunteers shows that Deck significantly reduces the query delay by up to 30x compared to baselines. Our microbenchmarks also demonstrate that the standalone overhead of Deck is negligible.