Relay Mining presents a scalable solution employing probabilistic mechanisms, crypto-economic incentives, and new cryptographic primitives to estimate and prove the volume of Remote Procedure Calls (RPCs) made from a client to a server. Distributed ledgers are designed to secure permissionless state transitions (writes), highlighting a gap for incentivizing full non-validating nodes to service non-transactional (read) RPCs. This leads applications to have a dependency on altruistic or centralized off-chain Node RPC Providers. We present a solution that enables multiple RPC providers to service requests from independent applications on a permissionless network. We leverage digital signatures, commit-and-reveal schemes, and Sparse Merkle Sum Tries (SMSTs) to prove the amount of work done. This is enabled through the introduction of a novel ClosestMerkleProof proof-of-inclusion scheme. A native cryptocurrency on a distributed ledger is used to rate limit applications and disincentivize over-usage. Building upon established research in token bucket algorithms and distributed rate-limiting penalty models, our approach harnesses a feedback loop control mechanism to adjust the difficulty of mining relay rewards, dynamically scaling with network usage growth. By leveraging crypto-economic incentives, we reduce coordination overhead costs and introduce a mechanism for providing RPC services that are both geopolitically and geographically distributed. We use common formulations from rate limiting research to demonstrate how this solution in the Web3 ecosystem translates to distributed verifiable multi-tenant rate limiting in Web2.

翻译：中继挖矿提出了一种可扩展的解决方案，利用概率机制、加密经济激励和新型密码学原语，来估算并证明客户端向服务器发起的远程过程调用（RPC）数量。分布式账本旨在保障无许可状态转换（写入操作）的安全性，这凸显了在激励全量非验证节点以服务非交易性（读取）RPC方面的空白，导致应用程序依赖于利他性或中心化的链下节点RPC提供商。我们提出了一种解决方案，使得多个RPC提供商能够在无许可网络上服务于独立应用的请求。我们利用数字签名、提交-揭示方案和稀疏Merkle求和树（SMST）来证明已完成的工作量。这一目标通过引入一种新颖的ClosestMerkleProof包含证明方案得以实现。分布式账本上的原生加密货币用于对应用程序进行速率限制，并抑制过度使用。基于令牌桶算法和分布式速率限制惩罚模型的既有研究，我们的方法利用反馈回路控制机制来调整中继奖励挖矿的难度，并随网络使用量的增长动态扩展。通过利用加密经济激励，我们降低了协调开销成本，并引入了一种提供地理政治与地理分布双维度分散的RPC服务的机制。我们采用速率限制研究中的常见公式，展示了该解决方案在Web3生态系统中如何转化为Web2中的分布式可验证多租户速率限制。