Catching the Fly: Practical Challenges in Making Blockchain FlyClient Real
Pericle Perazzo, Dario Capecchi
TLDR
This paper makes FlyClient practical by proposing a new adversary model, implementing it on Zcash, and optimizing proof size.
Key contributions
- Introduces an alternative adversary model for FlyClient, enabling economic parametrization and saving proof space.
- Provides the first practical FlyClient prover implementation for Zcash, evaluating its performance under various configurations.
- Introduces and evaluates two optimizations to minimize FlyClient proof sizes, one of which requires no consensus changes.
Why it matters
FlyClient is crucial for lightweight blockchain verification in resource-constrained environments. This paper makes the protocol production-ready, bridging the gap between theory and deployment. This enables broader adoption and more efficient blockchain interactions.
Original Abstract
FlyClient is a lightweight blockchain verification protocol that enables proof-of-work validation using minimal data, making it ideal for resource-constrained environments like mobile wallets, Internet-of-Things devices or cross-chain bridges implemented with smart contracts. Despite its strong potential for enabling lightweight blockchain verification, FlyClient protocol is still in the experimental stages, with limited real-world deployments and performance evaluations under diverse conditions. In this paper we bridge the gap between theory and deployment, by addressing several technical challenges to advance FlyClient to a production-ready solution. Namely, our contribution is three-fold: (i) we formally introduce an adversary model alternative to the original FlyClient one, that allows us to parametrize a verifier under a concrete economic interpretation, while also saving some proof space; (ii) we provide the first practical FlyClient prover implementation for a production blockchain (Zcash), and we estimate its performance under different configurations; (iii) we introduce and evaluate two optimizations that minimize the size of FlyClient proofs, the first of which does not require any consensus change.
📬 Weekly AI Paper Digest
Get the top 10 AI/ML arXiv papers from the week — summarized, scored, and delivered to your inbox every Monday.