Abstract: An efficient and robust Byzantine Fault Tolerance (BFT) consensus protocol serves as the cornerstone of consortium blockchain applications. In existing proposal processes, most protocols require the primary node to transmit O(n²) signatures, which significantly impairs protocol efficiency. Some protocols achieve linear view change, where the primary node only needs to send O(n) signatures to verify the validity of proposals, but at the cost of sacrificing optimistic responsiveness or introducing an extra round of message exchange. To address these inherent trade-offs, this paper proposes Climber, a novel BFT consensus protocol that integrates linear view change, optimistic responsiveness, and two-phase commit into a unified framework. Specifically, during view change, the newly-elected primary node enumerates all unlocked commitments generated in the previous view to prove proposal validity without adding extra commit phases, ensuring the protocol’s operational efficiency. Furthermore, the new primary node leverages aggregate signature technology to aggregate unlocked commitments from the same view into an unlocked certificate, reducing the communication complexity of view change to O(n). Additionally, a blacklist mechanism for malicious nodes is introduced, enabling the primary node to verify signatures with a time complexity of O(n). Simulation experiments are conducted under different network scales and malicious node ratios, and the results show that Climber not only maintains competitive throughput and latency performance but also exhibits superior robustness compared to Fast-Hotstuff, making it more suitable for large-scale consortium blockchain scenarios.