The Quest for Scalable Blockchain Fabric: Proof-of-Work vs. BFT Replication
The Quest for Scalable Blockchain Fabric: Proof-of-Work vs. BFT Replication
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DOI：
10.1007/978-3-319-39028-4_9
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发表时间：
2015-10
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影响因子：
--
通讯作者：
M. Vukolic
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文献类型：
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作者：
M. Vukolic
比特币加密货币展示了全球共识在数千个节点上的效用，永远改变了数字交易的世界。在比特币的早期，其基于概率工作量证明（PoW）的共识结构（也称为区块链）的性能并不是一个主要问题。尽管比特币的共识延迟大约为一小时，理论峰值吞吐量仅为每秒7笔交易，但它还是成为了一个成功的故事。今天的情况截然不同，早期PoW区块链的性能可扩展性差不再有意义。具体来说，以太坊等现代加密货币平台的趋势是支持在区块链结构上执行任意分布式应用程序，这需要更好的性能。然而，这种方法使加密货币平台远离其最初的目的，并进入数据库复制协议的领域，特别是经典状态机复制，特别是其拜占庭容错（BFT）变体。在本文中，我们将基于PoW的区块链与基于BFT状态机复制的区块链进行对比，重点关注其可扩展性限制。我们还讨论了最近提出的克服这些可扩展性限制的建议，并概述了在寻求“终极”区块链结构时存在的关键未决问题。
Bitcoin cryptocurrency demonstrated the utility of global consensus across thousands of nodes, changing the world of digital transactions forever. In the early days of Bitcoin, the performance of its probabilisticproof-of-work(PoW) based consensus fabric, also known asblockchain, was not a major issue. Bitcoin became a success story, despite its consensus latencies on the order of an hour and the theoretical peak throughput of only up to 7 transactions per second.The situation today is radically different and the poor performance scalability of early PoW blockchains no longer makes sense. Specifically, the trend of modern cryptocurrency platforms, such as Ethereum, is to support execution of arbitrary distributed applications on blockchain fabric, needing much better performance. This approach, however, makes cryptocurrency platforms step away from their original purpose and enter the domain of database-replication protocols, notably, the classicalstate-machine replication, and in particular its Byzantine fault-tolerant (BFT) variants.In this paper, we contrast PoW-based blockchains to those based on BFT state machine replication, focusing on their scalability limits. We also discuss recent proposals to overcoming these scalability limits and outline key outstanding open problems in the quest for the “ultimate” blockchain fabric(s).