區塊鏈共識演算法之比較與分析

區塊鏈技術已經是 2017 年最熱門的趨勢，許多大型公司已經將其應用於產品之中。不同的區塊鏈技術之間的競爭也堪稱百家爭鳴，各種技術的擁護者不停地強調自己的區塊鏈對於不同層面上的應用有多少功能。其中，為了讓加密貨幣的交易成功被執行，交易記錄必須經過確認後才能放進區塊鏈，而經過確認的過程是基於所謂的共識演算法進行的。而共識演算法是區塊鏈技術中關鍵的環節，他決定了所有參與者是如何在分散式系統中進行互動的，即使其中有一些參與者發生異常，最後還是能夠建立一致性的帳本，以利網路繼續運作。這篇論文我將針對數個共識演算法進行比較和分析，例如工作量證明、聯盟制工作量證明、權益證明、權威證明、實用型拜占庭容錯與伊斯坦堡拜占庭容錯。

關鍵字

區塊鏈；共識；拜占庭；工作量證明；比特幣；加密貨幣

並列摘要

Blockchain technologies top the lists of 2017’s hot trends. Many companies already back their products with blockchain technologies. Competitors use different approaches to blockchain technologies, emphasizing different aspects and pitching them as features to their customers. For cryptocurrency transactions to be conducted successfully, they need to be confirmed by the blockchain. These confirmations are based on what are referred to as consensus mechanisms. The consensus mechanism is a vital feature of a blockchain as it ensures that all participants of a distributed ledger are on the same page and enables the network to keep functioning even if some of its members are failing. In this essay, I will provide an comparison and analysis of several consensus, like Proof of Work, Consortium Proof of Work, Proof of Stake, Proof of Authority, Practical Byzantine Fault Tolerance, Istanbul Byzantine Fault Tolerance.