FPBFT: A Fast PBFT Protocol for Private Blockchains

Blockchain is an emerging technology that enables storing data and sharing it among many entities without the need for a central organization. Data is stored in an append-only ledger after the majority of participants agree on it. This mechanism is called the consensus, and many protocols are proposed in the literature (PoW, PoS, DPoS, RAFT, PBFT, etc.). In this paper, we focus on the Practical Byzantine Fault Tolerance (PBFT) protocol that has the advantages of being resilient to byzantine nodes, being faster than other protocols and energy saving in contrast to PoW. However, PBFT is not sufficiently scalable due to the important number of messages exchanged before consensus is reached which impacts the delays as well. In this paper, we propose FPBFT, a BFT protocol that is faster and more scalable than the traditional PBFT. We establish a scoring mechanism that eliminates slow and malicious nodes. In addition, PBFT steps are reduced following the SG-PBFT protocol and adapted to the blockchain use case. According to our experiments, our protocol performs better in terms of delays and communication traffic than PBFT and SG-PBFT.