  Smart meters enable improvements in electricity distribution system
efficiency at some cost in customer privacy. Users with home batteries can
mitigate this privacy loss by applying charging policies that mask their
underlying energy use. A battery charging policy is proposed and shown to
provide universal privacy guarantees subject to a constraint on energy cost.
The guarantee bounds our strategy's maximal information leakage from the user
to the utility provider under general stochastic models of user energy
consumption. The policy construction adapts coding strategies for
non-probabilistic permuting channels to this privacy problem.
