  This paper focuses on the new privacy challenges that arise in smart homes.
Specifically, the paper focuses on inferring the user's activities -- which
may, in turn, lead to the user's privacy -- via inferences through device
activities and network traffic analysis. We develop techniques that are based
on a cryptographically secure token circulation in a ring network consisting of
smart home devices to prevent inferences from device activities, via device
workflow, i.e., inferences from a coordinated sequence of devices' actuation.
The solution hides the device activity and corresponding channel activities,
and thus, preserve the individual's activities. We also extend our solution to
deal with a large number of devices and devices that produce large-sized data
by implementing parallel rings. Our experiments also evaluate the performance
in terms of communication overheads of the proposed approach and the obtained
privacy.
