Seahorse: Efficiently Mixing Encrypted and Normal Transactions
摘要
Blockchains have been proposed as solution against lack of transparency in the traditional finance domain. However, this does not directly prevent arbitrage, but it at least exposes it publicly. In response MEV (Miner Extractable Value) resilience mechanism have been proposed with one significant class of proposals focusing on encrypting sensitive transactions. These solutions, however, face a critical challenge in balancing transaction privacy, efficiency, and execution speed for non-encrypted transactions. Specifically, prior approaches either compromise privacy for non-committed transactions to achieve low latency or significantly increase communication complexity and processing time to maintain strong privacy guarantees against MEV attacks. This paper presents a novel hybrid approach specifically designed for MEV-resilience of blockchains. Our method employs a dual encryption scheme for each transaction: a per-transaction encryption that keeps contents private until commitment, and a per-event encryption enabling communication efficient batch processing after commitment. This technique maintains transaction confidentiality from submission until just before execution, while minimizing the delay non-encrypted transactions face. Our construction achieves \(O(n + B)\) communication complexity for B encrypted transactions and n nodes in optimistic environments, substantially improving upon existing MEV-resistant protocols.