Perennial Semantic Data Terms of Use for Decentralized Web
Rui Zhao, Jun Zhao
TL;DR
This work addresses the privacy and autonomy challenges of centralized Web platforms by introducing a perennial Data Terms of Use (DToU) language that separates data policy from application policy and supports automated reasoning. Built on semantic technologies (Turtle, Notation 3, RDF Surfaces) and integrated with Solid, it enables conformance, obligation, and policy-derivation checks to govern data usage and output data handling. The authors implement and benchmark a Solid-integrated DToU system using the EYE reasoner, demonstrating scalable reasoning across policy workloads and identifying bottlenecks tied to RDF Surfaces. The results suggest that perennial DToU can streamline user decisions, enhance privacy, and provide a practical path toward a privacy-respecting decentralized Web, while outlining optimization and usability improvements for real-world deployment.
Abstract
In today's digital landscape, the Web has become increasingly centralized, raising concerns about user privacy violations. Decentralized Web architectures, such as Solid, offer a promising solution by empowering users with better control over their data in their personal `Pods'. However, a significant challenge remains: users must navigate numerous applications to decide which application can be trusted with access to their data Pods. This often involves reading lengthy and complex Terms of Use agreements, a process that users often find daunting or simply ignore. This compromises user autonomy and impedes detection of data misuse. We propose a novel formal description of Data Terms of Use (DToU), along with a DToU reasoner. Users and applications specify their own parts of the DToU policy with local knowledge, covering permissions, requirements, prohibitions and obligations. Automated reasoning verifies compliance, and also derives policies for output data. This constitutes a ``perennial'' DToU language, where the policy authoring only occurs once, and we can conduct ongoing automated checks across users, applications and activity cycles. Our solution is built on Turtle, Notation 3 and RDF Surfaces, for the language and the reasoning engine. It ensures seamless integration with other semantic tools for enhanced interoperability. We have successfully integrated this language into the Solid framework, and conducted performance benchmark. We believe this work demonstrates a practicality of a perennial DToU language and the potential of a paradigm shift to how users interact with data and applications in a decentralized Web, offering both improved privacy and usability.