Unicity基础设施的无信任聚合层
The Trust-Free Aggregation Layer of the Unicity Infrastructure
AI总结：
该研究提出Unicity区块链基础设施的无信任聚合层，采用RSMT、Plonky3 STARK工具包等技术，实现无可信设置，达每秒万次插入及毫秒级验证的双重支付防护方案。
AI中文摘要：
Unicity是一种新型区块链基础设施，用于让用户执行链下点对点代币交易，同时以最小的区块链复杂度和存储量防止代币的并行状态（双重支付）。该基础设施的关键组件是聚合层，负责存储代币已花费状态的信息，并为用户提供无双重支付的紧凑密码学证明，且不牺牲任何信任。聚合层是第2层类型的服务，持有仅追加的键值存储库，定期使用我们称为共识层的传统区块链对其状态进行认证。每次认证变更状态时，聚合层都会向共识层提供关于键值存储库仅追加一致性的密码学证明。我们使用Radix稀疏默克尔树（RSMT）在每一轮i创建存储库的密码学摘要r_i，并使用特殊类型的认证路径来证明下一个摘要r_{i+1}是通过仅向存储库添加一些键值对（k,v）获得的。证明验证代码是在Plonky3 STARK工具包之上实现的代数中间表示（AIR）电路。我们的实现无需可信设置，在单个消费级CPU上实现了每秒10000次插入的吞吐量和毫秒级的验证时间。
英文摘要：
Unicity is a novel blockchain infrastructure for enabling users to execute off-chain peer-to-peer token transactions while preventing parallel states of tokens (double-spending) with minimal blockchain complexity and storage. A key component of the infrastructure is the Aggregation Layer responsible for storing information about the spent states of tokens and providing compact cryptographic proofs of no double-spending for the users without making any compromises in trust. Aggregation Layer is a layer 2 style service that holds an append-only key-value repository that periodically certifies its state using a traditional blockchain that we call the Consensus Layer. Every time while certifying a changed state the Aggregation Layer provides a cryptographic proof to the Consensus Layer about the append-only consistency of the key-value store. We use the Radix Sparse Merkle Trees (RSMTs) to create the cryptographic digest r_i of the store in every round i and authentication paths of special type in order to prove that the next digest r_{i+1} was obtained while only adding some key-value pairs (k,v) to the repository. The proof verification code is implemented as an Algebraic Intermediate Representation (AIR) circuit on top of the Plonky3 STARK toolkit. Our implementation uses no trusted setup, achieves throughput of 10,000 insertions per second and and millisecond range verification time on a single consumer-class CPU.
