Guppy: Efficient Light Clients via Recursive Zero-Knowledge Proofs

2026-09-07

AI Summary

Guppy通过让验证者仅承诺状态更新，并利用递归零知识证明维护完整的状态Merkle树，解决了传统轻客户端对验证者造成的负担问题。

Abstract

Traditional light clients rely on validators committing to the entire blockchain state at every block via a state commitment such as a Merkle tree, allowing clients to verify facts using short proofs. However, maintaining large and ever-growing state trees imposes a significant burden on validators and lies on the critical path of block production. As a result, many modern high-throughput chains avoid this approach altogether. This work asks whether efficient inclusion proofs can be supported without requiring validators to maintain full state commitments. We present Guppy, a protocol that achieves this by having validators commit to just the state updates. An off-chain, untrusted service, secured by recursive Zero-Knowledge Proofs (ZKPs), then maintains a verifiable Merkle tree over the full state. This design keeps validator overhead negligible and does not increase the asymptotic complexity of block construction. Our design rests on two key technical ideas. First, a hash-chain commitment moves validator signature verification out of the ZK circuit, keeping the proving circuit efficient. Second, we design a parallel recursive proving pipeline that leverages cheap recursion in modern ZKPs to ensure latency grows only logarithmically with throughput. Our Plonky2-based implementation demonstrates that Guppy can maintain a Merkle tree of size 2^30 while processing thousands of updates per second, adding only 2-4 s of latency.

Problem

• light clients
• blockchain state
• state commitment
• validators
• zero-knowledge proofs

Innovation

• Recursive Zero-Knowledge Proofs
• State Updates Commitment
• Hash-Chain Commitment
• Parallel Recursive Proving Pipeline