EVeCA: Efficient and Verifiable On-Chain Data Query Framework Using Challenge-Based Authentication

TL;DR

This work proposes an efficient and verifiable on-chain data query framework EVeCA, which effectively eliminates the need for on-chain ADS maintenance, and allows full nodes to participate in ADS maintenance in a cost-effective way.

Abstract

As blockchain applications become increasingly widespread, there is a rising demand for on-chain data queries. However, existing schemes for on-chain data queries face a challenge between verifiability and efficiency. Queries on blockchain databases can compromise the authenticity of the query results, while schemes that utilize on-chain Authenticated Data Structure (ADS) have lower efficiency. To overcome this limitation, we propose an efficient and verifiable on-chain data query framework EVeCA. In our approach, we free the full nodes from the task of ADS maintenance by delegating it to a limited number of nodes, and full nodes verify the correctness of ADS by using challenge-based authentication scheme instead of reconstructing them, which prevents the service providers from maintaining incorrect ADS with overwhelming probability. By carefully designing the ADS verification scheme, EVeCA achieves higher efficiency while remaining resilient against adaptive attacks. Our framework effectively eliminates the need for on-chain ADS maintenance, and allows full nodes to participate in ADS maintenance in a cost-effective way. We demonstrate the effectiveness of the proposed scheme through security analysis and experimental evaluation. Compared to existing schemes, our approach improves ADS maintenance efficiency by about 20*.

Figures (16)

• Figure 1: Data query process in a typical blockchain system. The user sends a query request to the full node, and the full node returns the query result to the user.
• Figure 2: Example of a Merkle tree
• Figure 3: An example illustrating verifiable query. In the traditional query processing (a), the user cannot verify the correctness of the query result. But in the verifiable query processing (b), the SP must return the query proof, with which the user can verify the correctness of the query result.
• Figure 4: System model of EVeCA. The task of constructing the ADS is assigned to a limited number of SP nodes, while full nodes are responsible for verifying the correctness of the ADS. Finally, users initiate verifiable query requests to the SPs that have passed the verification.
• Figure 5: System overview of EVeCA. In the ADS update phase, SPs extract on-chain data, update their local ADS and upload the digest of ADS to the blockchain. In the ADS verification phase, the challenge node generates a detecting token and request to SP, and full nodes verify the correctness of the returned result and proof. In the verifiable query phase, users send query request to the SP and verify the returned results based on the digest of ADS.

Theorems & Definitions (1)

• proof