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circom 新语法: 模板/数组 ​

最近，circom 添加了一些新的语言功能，以便更轻松地输入模板和传递数组。 在这里查看：https://github.com/iden3/circom/blob/master/mkdocs/docs/circom-language/anonymous-components-and-tuples.md

英文原文

Recently, circom added some new language features for easier inputting into templates and passing arrays around. Check it out here: https://github.com/iden3/circom/blob/master/mkdocs/docs/circom-language/anonymous-components-and-tuples.md

电路编译流程图 ​

当您开始使用 snarkjs 编译时，过程中生成了许多中间文件，要了解过程此图是必不可少的。 它是由 fvictorio 在 0xPARC 学习小组 期间制作的

circuit_compilation_diagram

英文原文

This diagram is essential as you start working with the many artifacts generated by the snarkjs compilation pipeline. It was made by fvictorio during the first 0xPARC Learning Group

snarkjs 步骤 ​

在 https://github.com/iden3/snarkjs 的 README 中有 27 个步骤。 在这里，我们分解它们的含义以及您可以跳过的内容：

(预备) 安装代码 ​

(步骤 0 - 8) 下载预计算 Tau ​

  • 这些步骤创建了一个“ptau”文件，其中存储了 snarkjs 运行所需的 tau 功能(第 5 节中涵盖的数学细节)

  • 你可以跳过自己设置这些； Polygon Hermez 已经完成了生成它们的仪式

  • 也可以简单下载一个预计算的 tau ，链接： https://github.com/iden3/snarkjs#7-prepare-phase-2，其中 tau 的幂次越高，电路中可包含的约束越多

(步骤 9 - 13) 电路编写+编译 ​

  • 在 zkrepl.dev 中完成电路后，您可以将代码复制到本地 circuit.circom 文件中
  • 需要指定公共/私人输入
  • circom circuit.circom --r1cs --wasm --sym 将生成您需要证明的所有附加文件
  • 第 11-13 步只是打印其他元数据或其他格式的 circom 文件

(步骤 14) 计算见证信息 ​

sh
circuit_js$ node generate_witness.js circuit.wasm ../input.json ../witness.wtns
circuit_js$ node generate_witness.js circuit.wasm ../input.json ../witness.wtns
  • 这使用从上一步生成的 JavaScript 文件 generate_witness.js，以及接收一个 input.json

(步骤 15 - 21) 计算证明key/可信设置阶段 2 ​

  • 在这里，我们生成相关元数据以在 .zkey 文件中创建证明，称为 proving key

  • 这需要一个“可信设置”，它在几个步骤中输入随机性以创建一个安全的证明密钥

    • 这通常会在许多方之间完成，只要他们不全部一起串通就是安全的

  • 你应该添加一些你自己的熵，如 https://github.com/iden3/snarkjs#16-contribute-to-the-phase-2-ceremony

(步骤 22, 25 - 26) 计算验证key ​

  • 在这里，我们计算相关元数据以在 .vkey.json 文件中验证证明，称为 verifying key
  • 也可以制作智能合约版本进行链上验证

(步骤 23 - 24) 创建和验证证明 ​

  • 可以在 CLI 中创建和验证证明，但也可以在 JavaScript 中为 Web 应用程序创建和验证证明
英文原文

In the README of https://github.com/iden3/snarkjs, there are 27 different steps that they tell you to follow. Here, we break down what they mean and which ones you can skip:

(Preliminaries) Installing code ​

(Steps 0 - 8) Download Powers of Tau ​

  • These steps create a “ptau” file which stores the powers of tau that are necessary for snarkjs to function (mathematical details covered in Session 5)

  • You can skip setting these up yourself; Polygon Hermez has already done a ceremony to generate them

  • Just download one from under https://github.com/iden3/snarkjs#7-prepare-phase-2 where there are more powers of tau than your circuit's constraints

(Steps 9 - 13) Circuit writing + compilation ​

  • After finishing your circuit in zkrepl.dev, you can copy the code into a local circuit.circom file
  • Need to specify public/private inputs
  • circom circuit.circom --r1cs --wasm --sym will generate all the additional files you need for proving
  • Steps 11-13 just print other metadata or the circom file in other formats

(Step 14) Computing the witness ​

sh
circuit_js$ node generate_witness.js circuit.wasm ../input.json ../witness.wtns
circuit_js$ node generate_witness.js circuit.wasm ../input.json ../witness.wtns
  • This uses the JavaScript file generate_witness.js generated from the previous step, as well as taking in an input.json

(Steps 15 - 21) Computing the proving key / trusted setup phase 2 ​

  • Here we generate the relevant metadata for creating proofs in a .zkey file, called a proving key

  • This requires a “trusted setup”, which inputs randomness across a few steps to create a secure proving key

    • This would usually be done over many parties and is secure as long as they don't all collude

  • You should add some entropy of your own as in https://github.com/iden3/snarkjs#16-contribute-to-the-phase-2-ceremony

(Step 22, Step 25-26) Computing the verification key ​

  • Here we compute the relevant metadata for verifying proofs in a .vkey.json file, called a verification key
  • Can also make a smart contract version for on-chain verification!

(Steps 23 - 24) Creating and verifying proofs ​

  • Can create and verify proofs in the CLI, but can also create and verify proofs in JavaScript for web apps