具動態安全性及每秒高交易量的工作量證明區塊鏈

A High-Throughput Proof-of-Work based Blockchain with Adaptive Security

陳秉玨(Bing-Jyue Chen)

指導教授 ： 林宗男

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202102231

摘要

由於區塊鏈能讓參與者在去中心的環境中達成對資料的共識，它在許多領域中扮演著重要的角色。在類比特幣協議中，所有的礦工都必須去競爭、檢查和確認每一個區塊。這樣子的設計隱含了一個思想：「所有的交易都必須用最高安全等級的規格來保護」。這個思想導致了今日區塊鏈的每秒交易吞吐量受限在一個非常低的常數值。在真實世界的應用中，不同交易的安全需求經常是相異的；根據這個想法，我們提出了一個每秒交易吞吐量能夠擴展的區塊鏈。該方法打破了現有區塊鏈在區塊安全上的限制，從而能夠更有效率地分配系統資源來確認各種具不同安全需求的交易。在我們的分析中，此區塊鏈能夠繼承類比特幣協議的「最終一致性」，這使得本系統的使用者既能享受低安全要求所帶來的低手續費，又不必擔心已確認的交易受到駭客的攻擊（即雙花攻擊）。在這之上，我們也實作了開源的模擬器，根據我們的模擬結果，能見我們的系統交易吞吐量可以達到現有系統的一百倍之上；同時，相比於現有系統，在此區塊鏈中等待過久仍未確認的交易也大幅減少了七成以上。

關鍵字

區塊鏈 ； 可擴展的系統交易量 ； 可調整的安全性 ； 工作量證明 ； 最終一致性

並列摘要

Blockchain plays an important role in a variety of fields because it enables peers to cooperate with each other in a decentralized database. In Bitcoin-like protocols, all blocks are always mined by all miners. This implies a design philosophy that all transactions should be protected with the highest security. As a result, the throughput is bounded by a low constant in these protocols. In real-world applications, the security requirement of transactions differs. Therefore, we present a novel blockchain structure, which breaks the limits of blockchain security so that we can distribute system resources efficiently to confirm transactions with different requirements. In our analysis, we show that the proposed system inherits eventual consistency in Bitcoin-like protocols. Moreover, our open-source simulation indicates that the system throughput of our system can be more than 100 times greater than that of baseline approaches; besides, the number of timeout transactions in the system can decrease by up to 70\% than that in a Bitcoin-like blockchain.

並列關鍵字

Blockchain ； Scalable throughput ； Adaptive security ； Proof-of-Work ； Eventual consistency

參考文獻

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