Optimistic Access Control for the Smart Home

One of the biggest privacy concerns of smart home users is enforcing limits on household members’ access to devices and each other’s data. While people commonly express preferences for intricate access control policies, in practice they often settle for less secure defaults. As an alternative, this paper investigates "optimistic access control" policies that allow users to obtain access and data without pre-approval, subject to oversight from other household members. This solution allows users to leverage the interpersonal trust they already rely on in order to establish privacy boundaries commensurate with more complex access control methods, while retaining the convenience of less secure strategies. To evaluate this concept, we conducted a series of surveys with 604 people total, studying the acceptability and perceptions of this approach. We found that a number of respondents preferred optimistic modes to existing access control methods and that interest in optimistic access varied with device type and household characteristics.