NeoBFT: Accelerating Byzantine Fault Tolerance Using Authenticated In-Network Ordering

Mission critical systems deployed in data centers today are facing more sophisticated failures. Byzantine fault-tolerant (BFT) protocols are capable of masking these types of failures, but are rarely deployed due to their performance cost and complexity. In this work, we propose a new approach to designing high performance BFT protocols in data centers. By re-examining the ordering responsibility between the network and the BFT protocol, we advocate a new abstraction offered by the data center network infrastructure. Concretely, we design a new authenticated ordered multicast primitive (aom) that provides transferable authentication and non-equivocation guarantees. Feasibility of the design is demonstrated by two hardware implementations of aom- one using HMAC and the other using public key cryptography for authentication - on new-generation programmable switches. We then co-design a new BFT protocol, NeoBFT, that leverages the guarantees of aom to eliminate cross-replica coordination and authentication in the common case. Evaluation results show that NeoBFT outperforms state-of-the-art protocols on both latency and throughput metrics by a wide margin, demonstrating the benefit of our new network ordering abstraction for BFT systems.