  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.
