IBFT 2.0: A Safe and Live Variation of the IBFT Blockchain Consensus Protocol for Eventually Synchronous Networks

TL;DR

IBFT 2.0 is a Byzantine fault-tolerant blockchain consensus protocol that ensures immediate finality, robustness in eventually synchronous networks, and supports dynamic validator sets, building upon and improving the original IBFT protocol.

Contribution

It introduces IBFT 2.0, enhancing safety and liveness in the IBFT protocol for blockchain consensus in asynchronous networks with dynamic validators.

Findings

Ensures immediate finality in blockchain consensus.

Robustness in an eventually synchronous network model.

Supports dynamic validator sets.

Abstract

In this work, we present IBFT 2.0 (Istanbul BFT 2.0), which is a Proof-of-Authority (PoA) Byzantine-fault-tolerant (BFT) blockchain consensus protocols that (i) ensures immediate finality, (ii) is robust in an eventually synchronous network model and (iii) features a dynamic validator set. IBFT 2.0, as the name suggests, builds upon the IBFT blockchain consensus protocol retaining all of the original features while addressing the safety and liveness limitations described in one of our previous works. In this paper, we present a high-level description of the IBFT 2.0 protocol and related robustness proof. Formal specification of the protocol and related formal proofs will be subject of a separate body of work. We also envision a separate work that will provide detailed implementation specifications for IBFT 2.0.