The mempool plays a crucial role in blockchain systems as a buffer zone for pending transactions before they are executed and included in a block. However, existing works primarily focus on mitigating defenses against already identified real-world attacks. This paper introduces secure blockchain-mempool designs capable of defending against any form of asymmetric eviction DoS attacks. We establish formal security definitions for mempools under the eviction-based attack vector. Our proposed secure transaction admission algorithm, named \textsc{saferAd-PR}, ensures eviction-security by providing a provable lower bound on the cost of executing eviction DoS attacks. Through evaluation with real transaction trace replays, \textsc{saferAd-PR} demonstrates negligible latency and significantly high lower bounds against any eviction attack, highlighting its effectiveness and robustness in securing blockchain mempools.

翻译：内存池在区块链系统中扮演着关键角色，作为交易被执行并打包入块前的待处理缓冲区。然而，现有研究主要集中于缓解针对已识别的现实攻击的防御措施。本文提出了能够抵御任何形式非对称驱逐型拒绝服务攻击的安全区块链内存池设计方案。我们为基于驱逐的攻击向量下的内存池建立了形式化的安全定义。我们提出的安全交易准入算法 \textsc{saferAd-PR} 通过为执行驱逐拒绝服务攻击的成本提供可证明的下界，确保了驱逐安全性。通过对真实交易轨迹回放的评估，\textsc{saferAd-PR} 在抵御任何驱逐攻击时表现出可忽略的延迟和显著高的成本下界，凸显了其在保护区块链内存池方面的有效性与鲁棒性。