论文标题
哈希图协议上的沉思：其安全性及其局限性
Musings on the HashGraph Protocol: Its Security and Its Limitations
论文作者
论文摘要
Hashgraph协议是一种拜占庭式容错的原子广播协议。它对本地存储的元数据的新颖使用允许当事方仅通过检查其本地数据来恢复其日志的一致排序，从而消除了对投票协议的需求。我们的论文的第一个贡献是为Hashgraph协议提供了重写的安全证明，该证明是遵循原子广播文献中使用的一致性和livese范式的。在我们的第二个贡献中，我们展示了一种新颖的对抗策略，该策略使协议从提交数据到日志的日志中停滞不前，以获得预期的指数次数。这证明了原始纸中的指数上限构想紧密。我们认为，我们的安全证明将使将Hashgraph与其他原子广播协议进行比较变得更加容易，并将其想法纳入新结构。我们还认为，我们的攻击可能会激发更多的研究对其他基于DAG的原子广播协议的类似攻击。
The HashGraph Protocol is a Byzantine fault tolerant atomic broadcast protocol. Its novel use of locally stored metadata allows parties to recover a consistent ordering of their log just by examining their local data, removing the need for a voting protocol. Our paper's first contribution is to present a rewritten proof of security for the HashGraph Protocol that follows the consistency and liveness paradigm used in the atomic broadcast literature. In our second contribution, we show a novel adversarial strategy that stalls the protocol from committing data to the log for an expected exponential number of rounds. This proves tight the exponential upper bound conjectured in the original paper. We believe that our proof of security will make it easier to compare HashGraph with other atomic broadcast protocols and to incorporate its ideas into new constructions. We also believe that our attack might inspire more research into similar attacks for other DAG-based atomic broadcast protocols.
