  In this paper we propose a novel protocol that allows suppliers and grid
operators to collect users' aggregate metering data in a secure and
privacy-preserving manner. We use secure multiparty computation to ensure
privacy protection. In addition, we propose three different data aggregation
algorithms that offer different balances between privacy-protection and
performance. Our protocol is designed for a realistic scenario in which the
data need to be sent to different parties, such as grid operators and
suppliers. Furthermore, it facilitates an accurate calculation of transmission,
distribution and grid balancing fees in a privacy-preserving manner. We also
present a security analysis and a performance evaluation of our protocol based
on well known multiparty computation algorithms implemented in C++.
