Christian Cachin, Klaus Kursawe, et al.
Journal of Cryptology
One of the main reasons why Byzantine fault-tolerant (BFT) systems are currently not widely used lies in their high resource consumption: 3f+1 replicas are required to tolerate only f faults. Recent works have been able to reduce the minimum number of replicas to 2f+1 by relying on trusted subsystems that prevent a faulty replica from making conflicting statements to other replicas without being detected. Nevertheless, having been designed with the focus on fault handling, during normal-case operation these systems still use more resources than actually necessary to make progress in the absence of faults. This paper presents Resource-efficient Byzantine Fault Tolerance (ReBFT), an approach that minimizes the resource usage of a BFT system during normal-case operation by keeping f replicas in a passive mode. In contrast to active replicas, passive replicas neither participate in the agreement protocol nor execute client requests; instead, they are brought up to speed by verified state updates provided by active replicas. In case of suspected or detected faults, passive replicas are activated in a consistent manner. To underline the flexibility of our approach, we apply ReBFT to two existing BFT systems: PBFT and MinBFT.
Christian Cachin, Klaus Kursawe, et al.
Journal of Cryptology
Elli Androulaki, Artem Barger, et al.
EuroSys 2018
Christian Cachin, Idit Keidar, et al.
Information Processing Letters
Christian Cachin, Marko Vukolic
DISC 2017