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.

翻译：在当今数字环境中，网络日益中心化，引发了用户隐私被侵犯的担忧。去中心化网络架构（如Solid）通过赋予用户在其个人"Pods"中更好地控制数据的能力，提供了一种有前景的解决方案。然而，一个重大挑战依然存在：用户必须浏览众多应用程序来决定哪些应用可以信任并授权其访问数据Pods。这通常涉及阅读冗长复杂的《使用条款》协议，用户往往感到望而生畏或直接忽略这一过程。这损害了用户自主性，并阻碍了数据滥用的检测。我们提出了一种新颖的数据使用条款（DToU）形式化描述，以及一个DToU推理器。用户和应用程序根据本地知识分别指定DToU策略中各自的部分，涵盖许可、要求、禁止和义务。自动化推理验证合规性，并推导出输出数据的策略。这构成了一种"永久性"DToU语言，策略制定仅需一次，即可在用户、应用程序及活动周期之间进行持续自动化检查。我们的解决方案基于Turtle、Notation 3和RDF Surfaces构建语言及推理引擎，确保与其他语义工具无缝集成以增强互操作性。我们已成功将该语言集成到Solid框架中，并进行了性能基准测试。我们相信，这项工作证明了永久性DToU语言的实用性，以及用户与去中心化网络中的数据和应用程序交互方式发生范式转变的潜力，在提升隐私保护的同时改善了可用性。