Nakamoto's seminal work gave rise to permissionless blockchains -- as well as a wide range of proposals to mitigate its performance shortcomings. Despite substantial throughput and energy efficiency achievements, most proposals only bring modest (or marginal) gains in transaction commit latency. Consequently, commit latencies in today's permissionless blockchain landscape remain prohibitively high for latency-sensitive geo-distributed applications. This paper proposes NimbleChain, which extends standard permissionless blockchains with a fast path that delivers consensusless promises of commitment. This fast path supports cryptocurrency transactions and only takes a small fraction of the original commit latency, while providing consistency guarantees that are strong enough to ensure correct cryptocurrencies. Since today's general-purpose blockchains also support smart contract transactions, which typically have (strong) sequential consistency needs, NimbleChain implements a hybrid consistency model that also supports strongly-consistent applications. To the best of our knowledge, NimbleChain is the first system to bring together fast consensusless transactions with strongly-consistent consensus-based transactions in a permissionless setting. We implement NimbleChain as an extension of Ethereum and evaluate it in a 500-node geo-distributed deployment. The results show that the average latency to promise a transaction is an order of magnitude faster than consensus-based commit, with minimal overhead when compared with a vanilla Ethereum implementation.
翻译:中本的开创性工作产生了不放任的连锁链 -- -- 以及一系列旨在减少其绩效缺陷的范围广泛的建议。尽管取得了大量的吞吐量和能源效率成就,但大多数建议只带来少量(或少量)交易收益,从而在交易中造成潜伏。因此,在今天的无放任的连锁板面上造成迟滞,对于延缓性敏感的地理分布应用来说,这种迟缓性仍然高得令人望而却步。本文件提出了Nimblechain,它扩展了标准的无放任性连锁链,并提供了一条能迅速兑现无法达成共识的承诺的快道。这一快道支持了加密货币交易,并且只用了最初少量的延缓性交易,同时提供了足够的一致性保证,足以确保准确的加密。由于今天的通用连锁链也支持智能的合同交易,通常具有(强)相继的连续性需要,因此Nimblechchain采用一种混合一致性模式,同时也支持高度一致的应用。对于我们的知识而言,Nimble Chain是第一个将快速的不通性交易与高度一致的、基于共识的交易结合起来的系统,而在一个平坦性交易中以平坦性交易中以显示一个平平平平平的扩展的结果。