论文标题
togcom：不对称的Sybil防御
ToGCom: An Asymmetric Sybil Defense
论文作者
论文摘要
工作证明（POW）是防御Sybil攻击的最常见技术之一。不幸的是，当前的战俘防御有两个主要缺点。首先，即使在没有攻击的情况下，他们也需要完成工作。其次，在攻击期间，他们需要良好的身份（ID）才能与攻击者一样多。 古普塔（Gupta），赛亚（Saia）和杨（Young）的最新理论工作表明，有可能克服这两个缺点。特别是，他们描述了一种新算法GMCOM，它始终确保少数ID是Sybil。他们表明，所有好ID的执行计算的速率为$ O（J_G + \ \ sqrt {t（j_g + 1）}）$，其中$ j_g $是良好IDS的联接率，而$ t $是对手执行计算的速率。 不幸的是，这种成本仅在（1）GMCOM始终知道良好ID的联接率的情况下才能达到。 （2）有一个固定的恒定时间将加入事件通过良好的ID分开。在这里，我们提出了Togcom，它消除了这两个缺点。为此，我们设计和分析了一种估计良好ID的联接率的机制；还设计了一种新方法来设置加入系统的计算成本。此外，我们还评估了TOGCOM的性能以及先前的基于POW的防御能力。根据我们的实验，我们设计了启发式方法，以进一步提高TOGCOM的性能，高达3美元的数量级比以前的SYBIL防御。
Proof-of-work (PoW) is one of the most common techniques to defend against Sybil attacks. Unfortunately, current PoW defenses have two main drawbacks. First, they require work to be done even in the absence of an attack. Second, during an attack, they require good identities (IDs) to spend as much as the attacker. Recent theoretical work by Gupta, Saia, and Young suggests the possibility of overcoming these two drawbacks. In particular, they describe a new algorithm, GMCom, that always ensures that a minority of IDs are Sybil. They show that rate at which all good IDs perform computation is $O(J_G + \sqrt{T(J_G+1)})$, where $J_G$ is the join rate of good IDs, and $T$ is the rate at which the adversary performs computation. Unfortunately, this cost bound only holds in the case where (1) GMCom always knows the join rate of good IDs; and (2) there is a fixed constant amount of time that separates join events by good IDs. Here, we present ToGCom, which removes these two shortcomings. To do so, we design and analyze a mechanism for estimating the join rate of good IDs; and also devise a new method for setting the computational cost to join the system. Additionally, we evaluate the performance of ToGCom alongside prior PoW-based defenses. Based on our experiments, we design heuristics that further improve the performance of ToGCom by up to $3$ orders of magnitude over these previous Sybil defenses.
