AI 中文总结
提出首个区块链可验证时间序列查询框架VeriTS，通过认证聚合区间树实现高效可验证查询，验证效率与证明大小较单记录证明大幅优化。
AI 中文摘要
区块链数据具有时间性，每笔交易都带有时间戳，且区块链施加了全序，因此链上数据形成了按源划分的时间序列流。然而，现有系统仅支持对区块和交易的基础查找，无法回答时间范围检索、窗口聚合等时间序列查询。将查询卸载到链下可恢复表达能力，但链下查询层不可信，因此结果必须可验证。为此，我们提出VeriTS，首个面向区块链系统的可验证时间序列查询框架，它无需修改区块链存储结构即可支持高效的范围查询与聚合查询。VeriTS维护一个链下查询层，通过认证聚合区间树表示每个流，该树同时作为查询索引和认证数据结构，因此窗口聚合可通过折叠对数级数量的节点聚合来回答。VeriTS通过最小覆盖集验证完整性，通过聚合折叠验证正确性；它将这两种保证扩展到模型段上的近似路径，在有界误差下重新定义完整性与正确性。矿工验证模型的残差而非重放其计算，因此即使是对抗性编码器也能增大证明大小和答案宽度，但无法篡改正确性。实验表明，在窗口聚合任务中，VeriTS的验证效率比单记录证明提升了两个数量级以上，范围查询证明的大小最多缩小14.5倍。
英文摘要
Every blockchain transaction carries a timestamp, and the chain imposes a total order. On-chain data therefore forms per-source time-series streams. However, existing systems support only basic lookups on blocks and transactions, and cannot answer time-series queries such as time-range retrieval and windowed aggregation. Offloading queries off-chain restores expressiveness, but the off-chain query layer is untrusted, so results must be verifiable. To this end, we propose VeriTS, the first verifiable time-series query framework for blockchain systems. It supports efficient range and aggregation queries. VeriTS maintains an off-chain query layer. In this layer, each stream is kept under one tree whose nodes carry authenticated aggregates, so the query index is itself the authenticated data structure. A light client thus verifies a windowed aggregate from a logarithmic number of authenticated nodes rather than from every record. VeriTS further answers error-tolerant queries from compact model representations of a stream, and extends the completeness and soundness guarantees to such approximate answers. As VeriTS never trusts the model behind a representation, a faulty or adversarial model can only widen an answer's certified interval, never falsify it. Experiments offer evidence that on windowed aggregation, VeriTS improves verification efficiency by more than two orders of magnitude over per-record proofs. On range retrieval, proofs shrink by up to 14.5x.
