  The introduction of Bitcoin fueled the development of blockchain-based
resilient data management systems that are resilient against failures, enable
federated data management, and can support data provenance. The key factor
determining the performance of such resilient data management systems is the
consensus protocol used by the system to replicate client transactions among
all participants. Unfortunately, existing high-throughput consensus protocols
are costly and impose significant latencies on transaction processing, which
rules out their usage in responsive high-performance data management systems.
  In this work, we improve on this situation by introducing the
Proof-of-Execution consensus protocol (PoE), a consensus protocol designed for
high-performance low-latency resilient data management. PoE introduces
speculative execution, which minimizes latencies by starting execution before
consensus is reached, and PoE introduces proof-of-executions to guarantee
successful execution to clients. Furthermore, PoE introduces a single-round
check-commit protocol to reduce the overall communication costs of consensus.
Hence, we believe that PoE is a promising step towards flexible general-purpose
low-latency resilient data management systems.
