Efficient Query Verification for Blockchain Superlight Clients Using SNARKs

As blockchain-based decentralized applications continue to gain adoption, an increasing number of users wish to interact with them, inspect their state, and extract meaningful insights from on-chain activity. However, due to the decentralized nature of blockchains, safely accessing such information typically requires running a full node, maintaining a local copy of the ledger. This can be prohibitive for resource-constrained users, as the ledger size grows continuously. In practice, most users rely on lightweight clients that query blockchain data through remote servers, without verifying the integrity of the responses. In many real-world scenarios, application-specific queries can only be answered by a small number of servers, sometimes all controlled by a single entity, thus reintroducing a single point of failure. In this work, we present an architecture that enables superlight clients (i.e., clients unwilling or unable to download full transaction data) to outsource query execution to untrusted servers while still receiving trustworthy results. Our design leverages the power of SNARKs to ensure verifiable computation, made practical through data accessed from full nodes and blockchain explorers, and optionally supported by smart contracts. We validate the feasibility of our approach through experimental evaluation on concrete use cases. Our results pave the way toward truly decentralized and reliable blockchain-based information systems, accessible even from constrained devices such as smartphones.