Proof-of-Stake Longest Chain Protocols: Security vs Predictability
Proof-of-Stake Longest Chain Protocols: Security vs Predictability
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DOI：
10.1145/3560829.3563559
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发表时间：
2019-10
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影响因子：
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通讯作者：
V. Bagaria;A. Dembo;Sreeram Kannan;Sewoong Oh;David Tse;P. Viswanath;Xuechao Wang;O. Zeitouni
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文献类型：
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作者：
V. Bagaria;A. Dembo;Sreeram Kannan;Sewoong Oh;David Tse;P. Viswanath;Xuechao Wang;O. Zeitouni
Nakamoto最长链协议非常简单，并且已被证明可以提供安全性，以对抗任何低于50%的总哈希功率的对手。权益证明（PoS）协议是一种节能的替代方案;然而，采用中本聪最长链设计的现有协议只能通过允许长期可预测性来实现可证明的安全性，使系统受到严重的贿赂攻击。在本文中，我们证明了具有与Nakamoto的PoW协议相似的可预测性的自然最长链PoS协议可以以低于总风险的1/（1+e）的比例实现针对任何对手的安全性。此外，我们提出了一个新的最长链PoS协议族，并正式证明了它们对50%对手的安全性，同时只需要短期的可预测性。
The Nakamoto longest chain protocol is remarkably simple and has been proven to provide security against any adversary with less than 50% of the total hashing power. Proof-of-stake (PoS) protocols are an energy efficient alternative; however existing protocols adopting Nakamoto's longest chain design achieve provable security only by allowing long-term predictability, subjecting the system to serious bribery attacks. In this paper, we prove that a natural longest chain PoS protocol with similar predictability as Nakamoto's PoW protocol can achieve security against any adversary with less than 1/(1+e) fraction of the total stake. Moreover we propose a new family of longest chain PoS protocols with a formal proof of their security against a 50% adversary, while only requiring short-term predictability.