We introduce APoW, a novel proof-of-work (PoW) construction inspired by Hashcash-style nonce searching, which enables the auditing of other miners' work through accountable re-scanning of the nonce space. The proposed scheme allows a miner to probabilistically attest to having searched specified regions of the nonce space in earlier mining rounds, while concurrently earning rewards for performing productive work for a new block or pool share. This capability enables miners belonging to a mining pools to audit another miner's claimed effort retroactively, thereby allowing the probabilistic detection of block withholding attacks (BWAs) without requiring trusted hardware or trusted third parties. As a consequence, the construction supports the design of decentralized mining pools in which work attribution is verifiable and withholding incentives are substantially reduced. The scheme preserves the fundamental properties of conventional PoW, including public verifiability and difficulty adjustment, while adding an orthogonal auditability layer tailored to pool-based mining. Finally, while a full deployment of APoW in Bitcoin would require a consensus rule change and minor modifications to mining ASICs, the construction remains practically useful even without consensus changes, for instance, as a pool-level auditing mechanism that enables verifiable pay-for-auditing using existing pool reserves.

翻译：本文提出APoW，一种受Hashcash式随机数搜索启发的新型工作量证明构造，通过对随机数空间进行可追责的重复扫描，实现对其他矿工工作的审计。该方案允许矿工以概率方式证明其已在早期挖矿轮次中搜索过指定的随机数空间区域，同时通过为新区块或矿池份额执行有效工作来获取收益。此能力使矿池中的矿工能够追溯性地审计其他矿工所宣称的工作量，从而在无需可信硬件或可信第三方的情况下实现区块扣留攻击的概率性检测。因此，该构造支持去中心化矿池的设计，其中工作归属可验证，扣留动机被大幅削弱。本方案保留了传统工作量证明的基本特性，包括公开可验证性与难度调整机制，同时增加了专为矿池挖矿设计的正交可审计层。最后，虽然在比特币中全面部署APoW需要修改共识规则并对挖矿ASIC进行微小调整，但该构造即使在没有共识变更的情况下仍具有实际应用价值，例如作为矿池层级的审计机制，可利用现有矿池储备实现可验证的按审计付费。