PFirewall: Semantics-Aware Customizable Data Flow Control for Smart Home Privacy Protection

• DOI: 10.14722/ndss.2021.24464
• Publication Date: 2021-03-13T23:31:12Z
• Authors: Haotian Chi; Qiang Zeng; Xiaojiang Du; Lannan Luo
• Keywords: FOS: Computer and information sciences; Computer Science - Cryptography and Security; 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; Cryptography and Security (cs.CR)

A new version of a previous submission with arXiv identifier arXiv:1910.07987. This version cannot be merged to the previous submission due to a title change<br/>Internet of Things (IoT) platforms enable users to deploy home automation applications. Meanwhile, privacy issues arise as large amounts of sensitive device data flow out to IoT platforms. Most of the data flowing out to a platform actually do not trigger automation actions, while homeowners currently have no control once devices are bound to the platform. We present PFirewall, a customizable data-flow control system to enhance the privacy of IoT platform users. PFirewall automatically generates data-minimization policies, which only disclose minimum amount of data to fulfill automation. In addition, PFirewall provides interfaces for homeowners to customize individual privacy preferences by defining user-specified policies. To enforce these policies, PFirewall transparently intervenes and mediates the communication between IoT devices and the platform, without modifying the platform, IoT devices, or hub. Evaluation results on four real-world testbeds show that PFirewall reduces IoT data sent to the platform by 97% without impairing home automation, and effectively mitigates user-activity inference/tracking attacks and other privacy risks.<br/>