Fault-tolerant privacy-preserving statistics

Abstract

Real-time statistics on smart meter consumption data must preserve consumer privacy and tolerate smart meter failures. Existing protocols for this private distributed aggregation model suffer from various drawbacks that disqualify them for application in the smart energy grid. Either they are not fault-tolerant or if they are, then they require bi-directional communication or their accuracy decreases with an increasing number of failures. In this paper, we provide a protocol that fixes these problems and furthermore, supports a wider range of exchangeable statistical functions and requires no group key management. A key-managing authority ensures the secure evaluation of authorized functions on fresh data items using logical time and a custom zero-knowledge proof providing differential privacy for an unbounded number of statistics calculations. Our privacy-preserving protocol provides all the properties that make it suitable for use in the smart energy grid. © Springer-Verlag Berlin Heidelberg 2012.