This paper presents BBCA-LEDGER, a Byzantine log replication technology for partially synchronous networks enabling blocks to be broadcast in parallel, such that each broadcast is finalized independently and instantaneously into an individual slot in the log. Every finalized broadcast is eventually committed to the total ordering, so that all network bandwidth has utility in disseminating blocks. Finalizing log slots in parallel achieves both high throughput and low latency. BBCA-LEDGER is composed of two principal protocols that interweave together, a low-latency/high-throughput happy path, and a high-throughput DAG-based fallback path. The happy path employs a novel primitive called BBCA, a consistent broadcast enforcing unique slot numbering. In steady state, BBCA ensures that a transaction can be committed with low latency, in just 3 network steps. Under network partitions or faults, we harness recent advances in BFT and build a fallback mechanism on a direct acyclic graph (DAG) created by BBCA broadcasts. In this manner, BBCA-LEDGER exhibits the throughput benefits of DAG-based BFT in face of gaps.

翻译：本文提出BBCA-LEDGER，一种面向部分同步网络的拜占庭日志复制技术，支持区块并行广播，使每次广播能独立即时完成并写入日志中的独立时隙。所有经最终确认的广播最终被纳入全局有序序列，确保全部网络带宽均用于区块分发。通过并行完成日志时隙的最终确认，实现了高通量与低延迟的双重目标。BBCA-LEDGER由两个核心协议交织构成：低延迟/高通量的快乐路径，以及基于有向无环图（DAG）的高通量回退路径。快乐路径采用名为BBCA的新型原语——一种强制唯一时隙编号的共识广播机制。在稳定状态下，BBCA仅需3个网络步骤即可实现交易的低延迟提交。当网络分区或故障发生时，我们利用BFT领域最新进展，在BBCA广播生成的DAG上构建回退机制。由此，BBCA-LEDGER在面对网络间隙时仍能保持DAG-BFT的吞吐量优势。