As an append-only distributed database, blockchain is utilized in a vast variety of applications including the cryptocurrency and Internet-of-Things (IoT). The existing blockchain solutions show downsides in communication and storage scalability, as well as decentralization. In this article, we propose LightChain, which is the first blockchain architecture that operates over a Distributed Hash Table (DHT) of participating peers. LightChain is a permissionless blockchain that provides addressable blocks and transactions within the network, which makes them efficiently accessible by all peers. Each block and transaction is replicated within the DHT of peers and is retrieved in an on-demand manner. Hence, peers in LightChain are not required to retrieve or keep the entire ledger. LightChain is fair as all of the participating peers have a uniform chance of being involved in the consensus regardless of their influence such as hashing power or stake. We provide formal mathematical analysis and experimental results (simulations and cloud deployment) to demonstrate the security, efficiency, and fairness of LightChain, and show that LightChain is the only existing blockchain that can provide integrity under the corrupted majority power of peers. As we experimentally demonstrate, compared to the mainstream blockchains such as Bitcoin and Ethereum, LightChain requires around 66 times smaller per node storage, and is around 380 times faster on bootstrapping a new node to the system, and each LightChain node is rewarded equally likely for participating in the protocol.

中文翻译：

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LightChain：基于 DHT 的可扩展区块链


作为一种仅追加的分布式数据库，区块链被广泛应用于加密货币和物联网 (IoT) 等各种应用中。现有的区块链解决方案在通信和存储可扩展性以及去中心化方面都存在缺陷。在本文中，我们提出了 LightChain，它是第一个在参与节点的分布式哈希表 (DHT) 上运行的区块链架构。 LightChain 是一种无需许可的区块链，可在网络内提供可寻址的区块和交易，从而使所有对等点都能有效地访问它们。每个区块和交易都在对等点的 DHT 中复制，并以按需方式检索。因此，LightChain 中的节点不需要检索或保留整个账本。光链是公平的，因为所有参与节点无论其算力或权益等影响力如何，都有统一的机会参与共识。我们提供正式的数学分析和实验结果（模拟和云部署）来证明LightChain的安全性、效率和公平性，并表明LightChain是现有的唯一能够在同行腐败的多数权力下提供完整性的区块链。正如我们的实验证明，与比特币和以太坊等主流区块链相比，LightChain 所需的每个节点存储空间减少了约 66 倍，引导新节点到系统的速度提高了约 380 倍，并且每个 LightChain 节点获得同等可能性的奖励参与协议。