The rapid expansion of the use of blockchain-based systems often leads to a choice between customizable private blockchains and more secure, scalable and decentralized but expensive public blockchains. This choice represents the trade-off between privacy and customization at a low cost and security, scalability, and a large user base but at a high cost. In order to improve the scalability of secure public blockchains while enabling privacy and cost reduction, zk-rollups, a layer 2 solution, appear to be a promising avenue. This paper explores the benefits of zk-rollups, including improved privacy, as well as their potential to support transactions designed for specific applications. We propose an innovative design that allows multiple zk-rollups to co-exist on the same smart contracts, simplifying their creation and customization. We then evaluate the first implementation of our system highlighting a low overhead on existing transaction types and on proof generation while strongly decreasing the cost of new transaction types and drastically reducing zk-rollup creation costs.

翻译：区块链系统的应用快速扩展往往导致在可定制化私有区块链与更安全、可扩展、去中心化但成本高昂的公有区块链之间进行选择。这一选择代表了低成本下的隐私性与定制化，与高成本下的安全性、可扩展性及大规模用户基础之间的权衡。为提升安全公有区块链的可扩展性，同时实现隐私保护与成本降低，作为二层解决方案的zk-Rollup展现出巨大潜力。本文深入探讨了zk-Rollup的优势（包括增强的隐私性）及其支持特定应用交易设计的潜力。我们提出一种创新架构，允许多个zk-Rollup在同一智能合约中共存，从而简化其创建与定制流程。随后，我们对系统首个实现方案进行评估，结果表明该方案在保持现有交易类型与证明生成低开销的同时，显著降低了新型交易类型的成本，并大幅减少了zk-Rollup的创建成本。