Position Paper: Denial-of-Service against Multi-Round Transaction Simulation

Transaction simulation is an important subsystem of block building, denial of whose service could lead to severe damage to the blockchain ecosystem and transaction delivery. Denial of block building has been studied, where the existing attack designs either target single-round builders, such as ConditionalExhaust (USENIX Security '24), or target two-round builders, by exploiting cross-round inconsistency, such as GhostTX (USENIX Security '24) and denial of sequencers (CCS '25). This work examines the denial-of-service security of multi-round transaction simulation under a new exploit: inter-transaction dependency that manifests in smart-contract state.