Blockchain has been exploited in many applications as a fundamental technology to construct trust and share data among multiple participants. A user with limited resources who runs a light node fetches data records stored on the blockchain by requesting a full node that maintains the complete blockchain data. As a type of broadly used query, top- queries which ask for data records with the highest values in a certain region can be useful in many blockchain scenarios. However, untrusted full nodes may return incorrect top- results. In this paper, we take the first step toward addressing the problem of verifiable blockchain top- queries without the help of a trusted third-party. First, we design a novel Sorted Merkle tree-based authenticated data structure and based on it we propose a new index named inverted SMT index that supports verifiable top- query with specific keyword conditions. Second, we propose a fundamental strawman design to support verifiable blockchain top- queries with arbitrary query regions. We further introduce two improved schemes, named segmentation design and sliding-window design, that overcome the efficiency obstacle of the strawman design. Finally, we confirm the efficiency of our solutions through an extensive experimental evaluation.

中文翻译：

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轻量级可验证区块链top-[公式省略]查询

区块链已在许多应用中被用作在多个参与者之间构建信任和共享数据的基础技术。运行轻节点的资源有限的用户通过请求维护完整区块链数据的全节点来获取存储在区块链上的数据记录。作为一种广泛使用的查询类型，top 查询要求特定区域中具有最高值的数据记录，在许多区块链场景中可能很有用。然而，不受信任的完整节点可能会返回不正确的顶级结果。在本文中，我们迈出了解决可验证区块链顶级查询问题的第一步，而无需可信第三方的帮助。首先，我们设计了一种新颖的基于排序 Merkle 树的认证数据结构，并在此基础上提出了一种名为倒排 SMT 索引的新索引，该索引支持具有特定关键字条件的可验证顶级查询。其次，我们提出了一种基本的稻草人设计，以支持具有任意查询区域的可验证区块链顶级查询。我们进一步介绍了两种改进方案，即分段设计和滑动窗口设计，克服了稻草人设计的效率障碍。最后，我们通过广泛的实验评估确认了我们解决方案的效率。