Centralized data silos are not only becoming prohibitively expensive but also raise issues of data ownership and data availability. These developments are affecting the industry, researchers, and ultimately society in general. Decentralized storage solutions present a promising alternative. Furthermore, such systems can become a crucial layer for new paradigms of edge-centric computing and web3 applications. Decentralized storage solutions based on p2p networks can enable scalable and self-sustaining open-source infrastructures. However, like other p2p systems, they require well-designed incentive mechanisms for participating peers. These mechanisms should be not only effective but also fair in regard to individual participants. Even though several such systems have been studied in deployment, there is still a lack of systematic understanding regarding these issues. We investigate the interplay between incentive mechanisms, network characteristics, and fairness of peer rewards. In particular, we identify and evaluate three core and up-to-date reward mechanisms for moving data in p2p networks: distance-based payments, reciprocity, and time-limited free service. Distance-based payments are relevant since libp2p Kademlia, which enables distance-based algorithms for content lookup and retrieval, is part of various modern p2p systems. We base our model on the Swarm network that uses a combination of the three mechanisms and serves as inspiration for our Tit-for-Token model. We present our Tit-for-Token model and develop a tool to explore the behaviors of these payment mechanisms. Our evaluation provides novel insights into the functioning and interplay of these mechanisms and helps. Based on these insights, we propose modifications to these mechanisms that better address fairness concerns and outline improvement proposals for the Swarm network.

翻译：中心化数据孤岛不仅成本日益高昂，还引发了数据所有权和数据可用性问题。这些发展正在影响产业界、研究人员，并最终波及整个社会。去中心化存储解决方案提供了一种有前景的替代方案。此外，此类系统可成为边缘计算和Web3应用新范式中的关键基础层。基于P2P网络的去中心化存储解决方案能够实现可扩展且自给自足的开源基础设施。然而，与其他P2P系统类似，该类系统需要为参与节点设计精良的激励机制。这些机制不仅需具备有效性，还需确保对个体参与者的公平性。尽管已有若干此类系统在实际部署中得到研究，但关于这些问题的系统性理解仍显不足。本文探究激励机制、网络特性与节点奖励公平性之间的相互作用。特别地，我们识别并评估了P2P网络中用于数据传输的三种核心且前沿的奖励机制：基于距离的支付、互惠机制以及有限时长的免费服务。由于支持基于距离内容查找与检索的libp2p Kademlia已被集成于多种现代P2P系统中，基于距离的支付机制具有重要研究价值。我们以Swarm网络为模型基础——该网络综合运用了上述三种机制，并启发了我们的Tit-for-Token模型。本文提出Tit-for-Token模型，并开发相应工具以探索这些支付机制的行为特征。我们的评估为理解这些机制的运行机制及交互关系提供了新颖见解。基于这些发现，我们提出能更好应对公平性问题的机制改进方案，并为Swarm网络的设计优化提供建议。