  In recent years, many proposals have arisen from research on privacy in smart
metering. In one of the considered approaches, referred to as anonymization,
smart meters transmit fine-grained electricity consumption values in such a way
that the energy supplier can not exactly determine procedence. This paper
measures the real privacy provided by such approach by taking into account that
at the end of a billing period the energy supplier collects the overall
electricity consumption of each meter for billing purposes. An entropy-based
measure is proposed for quantifying privacy and determine the extent to which
knowledge on the overall consumption of meters allows to re-identify anonymous
fine-grained consumption values.
