AggFT: Low-Cost Fault-Tolerant Smart Meter Aggregation with Proven Termination and Privacy

TL;DR

This paper introduces AggFT, a lightweight, fault-tolerant smart meter data aggregation protocol that enhances privacy, reduces computational costs, and guarantees proper termination even in failure scenarios, serving as a foundation for future research.

Contribution

It presents a novel fault-tolerant aggregation algorithm that combines masking and homomorphic encryption, with formal proofs of privacy and termination under failures.

Findings

Reduces computational costs of privacy-preserving aggregation

Ensures proper termination under a well-defined failure model

First algorithm supporting both masking and homomorphic encryption

Abstract

Smart meter data aggregation protocols have been developed to address rising privacy threats against customers' consumption data. However, these protocols do not work satisfactorily in the presence of failures of smart meters or network communication links. In this paper, we propose a lightweight and fault-tolerant aggregation algorithm that can serve as a solid foundation for further research. We revisit an existing error-resilient privacy-preserving aggregation protocol based on masking and improve it by: (i) performing changes in the cryptographic parts that lead to a reduction of computational costs, (ii) simplifying the behaviour of the protocol in the presence of faults, and showing a proof of proper termination under a well-defined failure model, (iii) decoupling the computation part from the data flow so that the algorithm can also be used with homomorphic encryption as a basis for privacy-preservation. To best of our knowledge, this is the first algorithm that is formulated for both, masking and homomorphic encryption. (iv) Finally, we provide a formal proof of the privacy guarantee under failure. The systematic treatment with strict proofs and the established connection to graph theory may also serve as a starting point for possible generalizations and improvements with respect to increased resilience.