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Title: Tyche: A Risk-Based Permission Model for Smart Homes
Emerging smart home platforms, which interface with a variety of physical devices and support third-party application development, currently use permission models inspired by smartphone operating systems—the permission to access operations are separated by the device which performs them instead of their functionality. Unfortunately, this leads to two issues: (1) apps that do not require access to all of the granted device operations have overprivileged access to them, (2) apps might pose a higher risk to users than needed because physical device operations are fundamentally risk-asymmetric — “door.unlock” provides access to burglars, and “door.lock” can potentially lead to getting locked out. Overprivileged apps with access to mixed-risk operations only increase the potential for damage. We present Tyche, a secure development methodology that leverages the risk-asymmetry in physical device operations to limit the risk that apps pose to smart home users, without increasing the user’s decision overhead. Tyche introduces the notion of risk-based permissions for IoT systems. When using risk-based permissions, device operations are grouped into units of similar risk, and users grant apps access to devices at that risk-based granularity. Starting from a set of permissions derived from the popular Samsung SmartThings platform, we conduct a user study involving domain-experts and Mechanical Turk users to compute a relative ranking of risks associated with device operations. We find that user assessment of risk closely matches that of domain experts. Using this insight, we define risk-based groupings of device operations, and apply it to existing SmartThings apps. We show that existing apps can reduce access to high-risk operations by 60% while remaining operable.  more » « less
Award ID(s):
1646392 1740897
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
2018 IEEE Cybersecurity Development (SecDev)
Page Range / eLocation ID:
29 to 36
Medium: X
Sponsoring Org:
National Science Foundation
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