Bitcoin is the first fully-decentralized permissionless blockchain protocol to achieve a high level of security, but at the expense of poor throughput and latency. Scaling the performance of Bitcoin has a been a major recent direction of research. One successful direction of work has involved replacing proof of work (PoW) by proof of stake (PoS). Proposals to scale the performance in the PoW setting itself have focused mostly on parallelizing the mining process, scaling throughput; the few proposals to improve latency have either sacrificed throughput or the latency guarantees involve large constants rendering it practically useless. Our first contribution is to design a new PoW blockchain Prism++ that has provably low latency and high throughput; the design retains the parallel-chain approach espoused in Prism but invents a new confirmation rule to infer the permanency of a block by combining information across the parallel chains. We show security at the level of Bitcoin with very small confirmation latency (a small constant factor of block interarrival time). A key aspect to scaling the performance is to use a large number of parallel chains, which puts significant strain on the system. Our second contribution is the design and evaluation of a practical system to efficiently manage the memory, computation, and I/O imperatives of a large number of parallel chains. Our implementation of Prism++ achieves a throughput of over 80,000 transactions per second and confirmation latency of tens of seconds on networks of up to 900 EC2 Virtual Machines.
翻译:Bitcoin是第一个完全分散放放放的无许可证的连锁协议,目的是实现高度安全,但以低流量和延迟性为代价。提高Bitcoin的绩效是最近一项主要研究方向。一个成功的工作方向是用利害证明取代工作证明(PoS)。关于扩大PoW本身业绩规模的建议主要侧重于平行采矿进程,扩大吞吐量;少数关于改善潜伏性的建议要么牺牲了吞吐量,要么是延缓性保证,导致其实际上毫无用处。我们的第一个贡献是设计一个新的PoW连锁链(Pitcoin),它具有明显的低密度和高流量;设计保留了在Prism(Posism)中支持的平行链(PoW)方法,但发明了一种新的确认规则,通过将平行性信息整合整个平行链的信息来推导出一个块的常态性。我们在比特肯级一级一级展示了安全性,而长期性延迟性保证度则非常小(一个小的固定性因素),使得这种保证实际上毫无用处。我们的连续性Prism Prism +Presm +++ 设计的第二个关键方面,扩大的绩效业绩的第二个关键方面是利用我们不断的大规模的系统,一个平行性交易系统对我们的不断进行大量的平行性评估。