Byzantine Fault Tolerant (BFT) consensus forms the foundation of many modern blockchains striving for both high throughput and low latency. A growing bottleneck is transaction execution and validation on the critical path of consensus, which has led to modular decoupled designs that separate ordering from execution: Consensus orders only metadata, while transactions are executed and validated concurrently. While this approach improves performance, it can leave invalid transactions in the ledger, increasing storage costs and enabling new forms of strategic behavior. We present the first systematic study of this setting, providing a formal framework to reason about the interaction between consensus and execution. Using this framework, we show that the decoupled design enables a previously unidentified attack, which we term gaslighting. We prove a fundamental trade-off between resilience to this attack and resource capacity utilization, where both are impossible to achieve deterministically in the decoupled model. To address this trade-off, we discuss an intermediate model for leader-based protocols that is robust to gaslighting attacks while achieving high throughput and low latency.

翻译：拜占庭容错（BFT）共识构成了许多现代区块链追求高吞吐量和低延迟的基础。一个日益突出的瓶颈在于共识关键路径上的交易执行与验证，这催生了将排序与执行解耦的模块化设计：共识仅对元数据进行排序，而交易则被并行执行和验证。尽管这种方法提升了性能，却可能导致无效交易留存于账本中，从而增加存储成本并催生新型策略性行为。我们首次对这一场景进行了系统性研究，提出了一个形式化框架以推演共识与执行间的交互关系。基于该框架，我们证明解耦设计会引发一种先前未被识别的攻击，我们称之为"煤气灯攻击"。我们严格论证了对此攻击的抵御能力与资源容量利用率之间存在根本性权衡，在解耦模型中二者无法同时确定性实现。为应对这一权衡，我们探讨了一种基于领导者协议的中介模型，该模型在实现高吞吐量与低延迟的同时，能够有效抵御煤气灯攻击。