  In this paper, we demonstrate how Hyperledger Fabric, one of the most popular
permissioned blockchains, can benefit from network-attached acceleration. The
scalability and peak performance of Fabric is primarily limited by the
bottlenecks present in its block validation/commit phase. We propose Blockchain
Machine, a hardware accelerator coupled with a hardware-friendly communication
protocol, to act as the validator peer. It can be adapted to applications and
their smart contracts, and is targeted for a server with network-attached FPGA
acceleration card. The Blockchain Machine retrieves blocks and their
transactions in hardware directly from the network interface, which are then
validated through a configurable and efficient block-level and
transaction-level pipeline. The validation results are then transferred to the
host CPU where non-bottleneck operations are executed. From our implementation
integrated with Fabric v1.4 LTS, we observed up to 12x speedup in block
validation when compared to software-only validator peer, with commit
throughput of up to 68,900 tps. Our work provides an acceleration platform that
will foster further research on hardware acceleration of permissioned
blockchains.
