A protocol for Metering Data Pseudonymization in Smart Grids

A tradeoff between data collection needs and user privacy is of paramount importance in the Smart Grid. This paper proposes a pseudonymization protocol for data gathered by the Smart Meters, which relies on a network infrastructure and a dedicated set of nodes, called Privacy Preserving Nodes (PPNs). The network privacy is enforced by a separation of duties: the PPNs perform data pseudonymization without having access to the measurements, which are masked by means of a secret sharing scheme, while the entities accessing the data recover and relate the plain measurements generated by the same meter along a time window of finite duration, but have no access to the meter identities. The paper also provides an evaluation of the security and of the performance of the protocol, comparing it to the two alternative encryption techniques which mask the measurements by means of the Chaum Mixing scheme or of an Identity Based Proxy Re-Encryption scheme.