PG: Byzantine Fault-Tolerant and Privacy-Preserving Sensor Fusion with Guaranteed Output Delivery

We design and implement PG, a Byzantine fault-tolerant and privacypreserving multi-sensor fusion system. PG is flexible and extensible, supporting a variety of fusion algorithms and application scenarios. On the theoretical side, PG develops and unifies techniques from dependable distributed systems and modern cryptography. PG can provably protect the privacy of individual sensor inputs and fusion results. In contrast to prior works, PG can provably defend against pollution attacks and guarantee output delivery, even in the presence of malicious sensors that may lie about their inputs, contribute ill-formed inputs, and provide no inputs at all to sway the final result, and in the presence of malicious servers serving as aggregators. On the practical side, we implement PG in the client-serversensor setting. Moreover, we deploy PG in a cloud-based system