GM! This blog post is the second part of the introductory series about AltLayer — a platform to allow application developers to launch highly scalable and disposable optimistic rollup-like execution layers. It can be seen as a system of individual optimistic rollups, each rollup tailored to a specific application.

GM！这篇博文是关于 AltLayer 的介绍系列文章的第二部分，AltLayer 是一个旨在使应用开发人员启动高度可扩展和一次性乐观汇总(optimistic rollup-ups)的执行层的平台。它可以看作是一个包含许多单独乐观汇总的系统，其中每个汇总都是针对特定应用量身定制的。

While the previous part of this introductory series is not a prerequisite reading for this post, we still recommend readers to read the first part that presents the “Why” of AltLayer. In this post, we focus on the “What” of AltLayer.

虽然本入门系列的前一部分不是阅读本文的先决条件，但我们仍然建议读者阅读第一部分，其中介绍了 AltLayer 的“为什么/原因”。在这篇文章中，我们关注 AltLayer 的“内容”。

Let’s dive in!

那就让我们一起深入了解吧！

什么是AltLayer (What is AltLayer?)

AltLayer is a hyper-scalable and disposable execution layer that relies on optimistic execution similar to optimistic rollups. It can be viewed as a Layer 3 protocol that derives its security directly from a Layer 1 or indirectly from a Layer 2 in a recursive manner. It is designed with the following key features:

AltLayer 是一个超可扩展的一次性执行层，它依赖于类似乐观汇总的乐观执行。它可以被视为 Layer 3 协议，其安全性直接来自 Layer 1 或间接来自 Layer 2 递归方式。它的设计具有以下主要功能：

1. Application-Tailored: Several applications such as GameFi, Metaverse, privacy-preserving applications among others often need specific tailoring or library support that is otherwise not available on a general purpose Layer 1 or Layer 2 due to the underlying limitation of the virtual machine. AltLayer not only comes with EVM support but also WASM support that will allow applications to access any web assembly code, thereby expanding the types of applications that can be built.

定制应用： GameFi、Metaverse、隐私保护等多个应用通常需要特定的定制或库支持，否则由于虚拟机的底层限制，这些应用在通用layer1或layer2 上会不可用. AltLayer 不仅提供 EVM 支持，还提供 WASM 支持，允许应用程序访问任何 Web 汇编代码，从而扩展可构建的应用类型。

2. Resource Optimized: Unlike all Layer 1s and Layer 2s, AltLayer presents a unique execution layer that can be instantiated at any time by a dApp developer, utilized for as long as needed, and then disposed of. AltLayer achieves this by providing a transient execution layer via a concept of flash layering. Flash layering comes with a plug-and-play and cloud-service-like solution called FlashLayer for dApp developers to use when the application expects a burst in demand. Once a FlashLayer is disposed of, all the related resources are freed and the dApp’s state is rolled up to the underlying Layer 1 chain. A dApp developer will have the economic (or other) incentives to free the FlashLayer when the blockspace on the underlying Layer 1 chain is not so scarce.

资源优化： 与所有layer1和layer2不同，AltLayer 提供了一个独特的执行层，可以由 dApp 开发人员随时实例化，根据需要使用，然后丢弃。 AltLayer 通过 flash layering(瞬时分层) 的概念提供瞬间执行层来实现这一点。 Flash 分层附带一个即插即用和类似云服务的解决方案，称为 FlashLayer(瞬时分层)，供 dApp 开发人员在应用预期需求激增时使用。一旦 FlashLayer 被释放，所有相关资源都会被释放，dApp 的状态会汇总到底层的layer1。当底层layer1上的区块空间不是那么稀缺时，dApp 开发人员将有经济（或其他）激励来释放_FlashLayer_ 。

3. Modular Design with Multi-VM support: AltLayer is designed to be a modular execution layer that performs optimistic execution and is easy to integrate with any Layer 1 or Layer 2 and therefore will have an outreach that spans developers across heterogeneous chains. Given the different runtime supported by different chains, AltLayer is designed to support multiple VMs in particular EVM and WASM among others.

具有多虚拟机 支持的模块化设计： AltLayer 被设计成一个模块化的执行层，可以进行乐观执行(optimistic execution)并且易于与任何layer1或layer2集成，因此将可触达/吸引异构链的开发人员。鉴于不同链支持不同运行时间，AltLayer被设计为支持多个虚拟机，特别是 EVM 和 WASM 等。

4. Tiered Security: AltLayer offers a three-tiered approach to security that caters to a user’s security budget:

分层安全性： AltLayer 提供了满足用户 安全预算 的三层安全方法：

a. Low Budget: Blocks in AltLayer are produced by block producers which are similar to sequencers in optimistic rollup implementations such as Arbitrum, but, instead of having only one sequencer as in Arbitrum, AltLayer has several block producers that reach consensus on the next block. This avoids a single point of failure and mitigates any censorship from a malicious sequencer. A user with a low security budget may decide to accept a block as soon as at least one honest block producer generates the correct block.

a.低预算： AltLayer 中的区块由区块生产者生产，类似于 Arbitrum 等乐观汇总实现中的序列器，但不同于 Arbitrum 中只有一个排序器，AltLayer 有几个区块生产者会就下一个区块达成共识。这避免了单点故障并减轻了来自恶意序列器的任何审查。一旦至少有一个诚实的区块生产者生成了正确的区块，安全预算较低的用户就可以决定接受区块。

b. Medium Budget: Once a block is produced, verifiers in AltLayer check the validity of the block. Verifiers re-execute transactions and compare the generated state root with the Merkle root committed by the block producers. Verifiers are also required to commit data to the underlying Layer 1. A user with medium security budget may decide to wait until a given block is verified by at least one verifier. Note that a verifier can be run on different platforms, e.g., commodity x86/ARM machines, web browsers, dApp backends or hardware-assisted environments.

b.中等预算: 一旦产生一个区块，AltLayer 中的验证者就会检查该区块的有效性。验证者重新执行交易，并将生成的状态根与块生产者提交的 Merkle 根进行比较。验证者还需要将数据提交到底层的layer1。具有中等安全预算的用户可以决定等到给定的块被至少一个验证者验证。请注意，验证程序可以在不同的平台上运行，例如商品级别的 x86/ARM 机器、Web 浏览器、dApp 后端或硬件辅助环境。

c. High Budget: As AltLayer ultimately derives security from the underlying Layer 1, a user with a high security budget may decide to wait until the FlashLayer is disposed of and when the dApp state gets rolled up to Layer 1. At this stage the security achieved is the same as that of the sovereign Layer 1.

C.高预算： 由于 AltLayer 最终从底层layer1获得安全性，因此具有高安全预算的用户可能会决定等到 FlashLayer 被销毁并且 dApp 状态汇总到layer1。在此阶段，安全性实现与主权layer1相同。

5. Highly elastic with extremely low latency: AltLayer presents a dApp developer with its own Layer 2 that is highly elastic and comes with very low latency. This is essentially because it implements an architecture similar to optimistic rollup design as in Arbitrum.

高弹性和极低延迟： AltLayer 为 dApp 开发人员提供了自己的layer2，该层具有高弹性和极低延迟。这本质上是因为它实现了类似于 Arbitrum 中的乐观汇总设计的架构。

何时上线 (Wen Launch?)

We have been building AltLayer since Q4 2021 and we are happy to announce that we have a fully functioning MVP and devnet ready. Those interested in understanding how AltLayer works, check out this blog post on our first NFT mint event on a disposable execution layer. Our next development milestone is to finalize an alpha Testnet with several big milestones to follow.

自 2021 年第四季度以来，我们一直在构建 AltLayer，我们很高兴地宣布，已经准备好功能齐全的 MVP 和 devnet。有兴趣了解 AltLayer 工作原理的人，请查看我们的博客文章，即在一次性执行层上的第一个 NFT铸币活动。我们的下一个发展里程碑是完成一个 alpha 测试网，其中包含的几个重要的里程碑(会在之后公布)。