IoT platforms enable users to connect various smart devices and online services via reactive apps running on the cloud. These apps, often developed by third-parties, perform simple computations on data triggered by external information sources and actuate the results of computations on external information sinks. Recent research shows that unintended or malicious interactions between the different (even benign) apps of a user can cause severe security and safety risks. These works leverage program analysis techniques to build tools for unveiling unexpected interference across apps for specific use cases. Despite these initial efforts, we are still lacking a semantic framework for understanding interactions between IoT apps. The question of what security policy cross-app interference embodies remains largely unexplored. This article proposes a semantic framework capturing the essence of cross-app interactions in IoT platforms. The framework generalizes and connects syntactic enforcement mechanisms to bisimulation-based notions of security, thus providing a baseline for formulating soundness criteria of these enforcement mechanisms. Specifically, we present a calculus that models the behavioral semantics of a system of apps executing concurrently, and use it to define desirable semantic policies targeting the security and safety of IoT apps. To demonstrate the usefulness of our framework, we define and implement static analyses for enforcing cross-app security and safety, and prove them sound with respect to our semantic conditions. We also leverage real-world apps to validate the practical benefits of our tools based on the proposed enforcement mechanisms.

中文翻译：

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友军之火

物联网平台使用户能够通过在云上运行的反应式应用程序连接各种智能设备和在线服务。这些应用程序通常由第三方开发，对外部信息源触发的数据执行简单的计算，并在外部信息接收器上执行计算结果。最近的研究表明，用户的不同（甚至是良性）应用程序之间的意外或恶意交互可能会导致严重的安全风险。这些作品利用程序分析技术来构建工具，以揭示针对特定用例的应用程序之间的意外干扰。尽管做出了这些初步努力，但我们仍然缺乏用于理解物联网应用程序之间交互的语义框架。跨应用程序干扰体现的安全策略问题在很大程度上仍未得到探索。本文提出了一个语义框架，捕捉物联网平台中跨应用交互的本质。该框架将句法执行机制概括并连接到基于双模拟的安全概念，从而为制定这些执行机制的健全性标准提供了基线。具体来说，我们提出了一种微积分，它对同时执行的应用程序系统的行为语义进行建模，并使用它来定义针对物联网应用程序安全性的理想语义策略。为了证明我们框架的有用性，我们定义并实施了静态分析以强制执行跨应用程序的安全性和安全性，并根据我们的语义条件证明它们是合理的。我们还利用现实世界的应用程序，根据建议的执行机制来验证我们工具的实际优势。