Scalable Byzantine Consensus via Hardware-assisted Secret Sharing
This addresses the problem of scaling blockchain consensus for financial institutions, offering a solution that is incremental by building on existing BFT protocols with new techniques.
The paper tackles the scalability limitation of Byzantine fault-tolerant (BFT) protocols, which are hindered by O(n^2) message complexity, by proposing FastBFT, a protocol that achieves low latency and high throughput for large-scale networks through hardware-assisted secret sharing and optimizations.
The surging interest in blockchain technology has revitalized the search for effective Byzantine consensus schemes. In particular, the blockchain community has been looking for ways to effectively integrate traditional Byzantine fault-tolerant (BFT) protocols into a blockchain consensus layer allowing various financial institutions to securely agree on the order of transactions. However, existing BFT protocols can only scale to tens of nodes due to their $O(n^2)$ message complexity. In this paper, we propose FastBFT, a fast and scalable BFT protocol. At the heart of FastBFT is a novel message aggregation technique that combines hardware-based trusted execution environments (TEEs) with lightweight secret sharing primitives. Combining this technique with several other optimizations (i.e., optimistic execution, tree topology and failure detection), FastBFT achieves low latency and high throughput even for large scale networks. Via systematic analysis and experiments, we demonstrate that FastBFT has better scalability and performance than previous BFT protocols.