The study of Proof of Work (PoW) has culminated with the introduction of cryptocurrency blockchains like Bitcoin. These protocols require their operators, called miners, to expend computational resources and they reward them with minted cryptocurrency tokens. The system is secure from attackers who cannot expend resources at a rate equivalent to that of all benign miners. But the resource requirement is arbitrary - the product of the number of minted tokens and their real value. We present Hybrid Expenditure Blockchain (HEB), a novel cryptocurrency PoW protocol that allows its designer to tune external expenditure. To the best of our knowledge, this is the first tunable PoW protocol. Despite the reduced resource expenditure, it maintains the security guarantees of pure PoW protocols against rational attacks. HEB has practical implications, as global power expenditure on PoW blockchains exceeds that of a medium-sized country. Applying HEB in operational PoW systems can significantly reduce their ecological footprint.

中文翻译：

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HEB：混合支出区块链

工作量证明 (PoW) 的研究随着比特币等加密货币区块链的引入而告终。这些协议要求他们的操作员（称为矿工）消耗计算资源，并用铸造的加密货币令牌奖励他们。该系统不会受到攻击者的攻击，攻击者无法以与所有良性矿工相同的速度消耗资源。但资源需求是任意的——铸造代币数量与其实际价值的乘积。我们提出了混合支出区块链 (HEB)，这是一种新颖的加密货币 PoW 协议，允许其设计者调整外部支出。据我们所知，这是第一个可调的 PoW 协议。尽管减少了资源支出，但它保持了纯 PoW 协议对理性攻击的安全保证。HEB 具有实际意义，因为 PoW 区块链的全球电力支出超过了一个中等国家。在可操作的 PoW 系统中应用 HEB 可以显着减少其生态足迹。