As of July 15, 2023, Ethererum, which is a Proof-of-Stake (PoS) blockchain [1] has around 410 Billion USD in total assets on chain (popularly referred to as total-value-locked, TVL) but has only 33 Billion USD worth of ETH staked in securing the underlying consensus of the chain [2]. A preliminary analysis might suggest that as the amount staked is far less (11x less) than the value secured, the Ethereum blockchain is insecure and "over-leveraged" in a purely cryptoeconomic sense. In this work, we investigate how Ethereum, or, more generally, any PoS blockchain can be made secure despite this apparent imbalance. Towards that end, we attempt to formalize a model for analyzing the cryptoeconomic safety of PoS blockchain, which separately analyzes the cost-of-corruption, the cost incurred by an attacker, and the profit-from-corruption, the profit gained by an attacker. We derive sharper bounds on profit-from-corruption, as well as new confirmation rules that significantly decrease this upper-bound. We evaluate cost-of-corruption and profit-from-corruption only from the perspective of attacking safety. Finally, we present a new "insurance" mechanism, STAKESURE, for allocating the slashed funds in a PoS system, that has several highly desirable properties: solving common information problem in existing blockchains, creating a mechanism for provably safe bridging, and providing the first sharp solution for automatically adjusting how much economic security is sufficient in a PoS system. Finally, we show that the system satisfies a notion of strong cryptoeconomic safety, which guarantees that no honest transactor ever loses money, and creates a closed system of Karma, which not only ensures that the attacker suffers a loss of funds but also that the harmed parties are sufficiently compensated.

翻译：截至2023年7月15日，作为权益证明（PoS）区块链[1]的以太坊链上总资产约为4100亿美元（通常称为总锁仓价值TVL），但用于保护链底层共识的质押ETH价值仅为330亿美元[2]。初步分析表明，由于质押金额远低于（相差11倍）所保护的价值，在纯粹加密经济意义上，以太坊区块链是不安全的且"过度杠杆化"。本研究探究以太坊（或更广泛而言任何PoS区块链）如何在面对这种明显失衡时仍能保持安全。为此，我们尝试形式化一个用于分析PoS区块链加密经济安全性的模型，该模型分别分析攻击成本（腐败成本）与攻击收益（腐败利润）。我们推导出更严格的腐败利润上界，以及能显著降低该上界的新型确认规则。我们仅从攻击安全性的角度评估腐败成本与腐败利润。最后，我们提出一种名为STAKESURE的新型"保险"机制，用于在PoS系统中分配罚没资金，该机制具有多个理想特性：解决现有区块链中的共同信息问题、创建可证明安全的跨链桥接机制，并提供首个能自动调整PoS系统所需经济安全充足性的精确解决方案。最终证明该系统满足强加密经济安全性概念，确保诚实交易者永不蒙受损失，并构建封闭的因果报应（Karma）系统——不仅保证攻击者遭受资金损失，还确保受害方获得充分补偿。