Alchemy University 学习教程，Blockchain Cryptography

估值102亿融资5.45亿的Alchemy 项目，大学每周任务逐步开始。持有大学生早期卡的伙伴们可以开始大学生活了：

官方大佬的 lens ，可以关注下：

了解更多，请关注作者：https://twitter.com/bitc2024

部分章节是看文章和视频的，自行查看哈，这里从实际操作开始。

The First Primitive

Cryptographic Hashes

1: Find Favorite Color

查看要求：

输入：

const { sha256 } = require("ethereum-cryptography/sha256");
const { toHex, utf8ToBytes } = require("ethereum-cryptography/utils");

// the possible colors that the hash could represent
const COLORS = ['red', 'green', 'blue', 'yellow', 'pink', 'orange'];

// given a hash, return the color that created the hash
function findColor(hash) {
    hex = toHex(hash);
    for(let i = 0; i < COLORS.length; i++) {
        b = utf8ToBytes(COLORS[i]);
        h = sha256(b);
        if (toHex(h) === hex) {
            return COLORS[i];
        }
    }
}

module.exports = findColor;

点击运行。

Digital Signatures

Public Key Exercise

1: Hash Message\ 查看要求：

输入：

const { keccak256 } = require("ethereum-cryptography/keccak");
const { utf8ToBytes } = require("ethereum-cryptography/utils");

function hashMessage(message) {
    return keccak256(utf8ToBytes(message));
}

module.exports = hashMessage;

点击运行。

2: Sign Message

输入：

const secp = require("ethereum-cryptography/secp256k1");
const hashMessage = require('./hashMessage');

const PRIVATE_KEY = "6b911fd37cdf5c81d4c0adb1ab7fa822ed253ab0ad9aa18d77257c88b29b718e";

async function signMessage(msg) {
    return secp.sign(hashMessage(msg), PRIVATE_KEY, { recovered : true});
}

module.exports = signMessage;

点击运行。

3: Recover Key

查看要求：

输入：

const secp = require("ethereum-cryptography/secp256k1");
const hashMessage = require("./hashMessage");

async function recoverKey(message, signature, recoveryBit) {
    return secp.recoverPublicKey(hashMessage(message), signature, recoveryBit);
}

module.exports = recoverKey;

点击运行。

4: Key to Address

查看要求：

输入：

const secp = require("ethereum-cryptography/secp256k1");
const { keccak256 } = require("ethereum-cryptography/keccak");

function getAddress(publicKey) {
    return keccak256(publicKey.slice(1)).slice(-20);
}

module.exports = getAddress;

点击运行。

Proof of Work

Proof of Work Miner

1: Mempool

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');
const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
const MAX_TRANSACTIONS = 10;

const mempool = [];
const blocks = [];

function addTransaction(transaction) {
    mempool.push(transaction);
}

function mine() {
}

module.exports = {
    TARGET_DIFFICULTY,
    MAX_TRANSACTIONS,
    addTransaction, 
    mine, 
    blocks,
    mempool
};

点击运行。

2: Mine Block

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');
const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
const MAX_TRANSACTIONS = 10;

const mempool = [];
const blocks = [];

function addTransaction(transaction) {
    mempool.push(transaction);
}

function mine() {
    let block = {id:blocks.length};
    blocks.push(block);
}

module.exports = {
    TARGET_DIFFICULTY,
    MAX_TRANSACTIONS,
    addTransaction, 
    mine, 
    blocks,
    mempool
};

点击运行。

3: Block Hash

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');
const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
const MAX_TRANSACTIONS = 10;

const mempool = [];
const blocks = [];

function addTransaction(transaction) {
    mempool.push(transaction);
}

function mine() {
    let block = {id:blocks.length};
    block.hash = SHA256(JSON.stringify(block));
    blocks.push(block);
}

module.exports = {
    TARGET_DIFFICULTY,
    MAX_TRANSACTIONS,
    addTransaction, 
    mine, 
    blocks,
    mempool
};

点击运行。

4: Mine TX

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');
const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
const MAX_TRANSACTIONS = 10;

const mempool = [];
const blocks = [];

function addTransaction(transaction) {
    mempool.push(transaction);
}

function mine() {
    let block = {id:blocks.length, transactions:[]};
    if (mempool.length > 0) {
        for (let i = 0; i < MAX_TRANSACTIONS; i++) {
            block.transactions.push(mempool[0]);
            mempool.shift();
            if (mempool.length <= 0) {
                break;
            }
        }
    }
    block.hash = SHA256(JSON.stringify(block));
    blocks.push(block);
}

module.exports = {
    TARGET_DIFFICULTY,
    MAX_TRANSACTIONS,
    addTransaction, 
    mine, 
    blocks,
    mempool
};

点击运行。

5: Difficulty

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');
const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
const MAX_TRANSACTIONS = 10;

const mempool = [];
const blocks = [];

function addTransaction(transaction) {
    mempool.push(transaction);
}

function mine() {
    let block = {id:blocks.length, transactions:[]};
    if (mempool.length > 0) {
        for (let i = 0; i < MAX_TRANSACTIONS; i++) {
            block.transactions.push(mempool[0]);
            mempool.shift();
            if (mempool.length <= 0) {
                break;
            }
        }
    }
    block.nonce = 0;
    block.hash = SHA256(JSON.stringify(block));
    let hash = block.hash;
    while (BigInt(`0x${hash}`) >= TARGET_DIFFICULTY) {
        block.nonce = block.nonce + 1;
        block.hash = SHA256(JSON.stringify(block));
        hash = block.hash;
    }
    blocks.push(block);
}

module.exports = {
    TARGET_DIFFICULTY,
    MAX_TRANSACTIONS,
    addTransaction, 
    mine, 
    blocks,
    mempool
};

点击运行。

Blockchain Network

Blockchain Data Structure

1: Blocks and Hashes

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');

class Block {
    constructor() {
    }
    toHash() {
        return SHA256("a string");
    }
}

module.exports = Block;

点击运行。

2: What's in a Hash?

查看要求：

输入：

const SHA256 = require('crypto-js/sha256');

class Block {
    constructor(data) {
        this.data = data; 
    }
    toHash() {
        return SHA256(this.data.toString());
    }
}

module.exports = Block;

点击运行。

3: The Genesis Block

查看要求：

输入：

const Block = require('./Block');

class Blockchain {
    constructor() {
        this.chain = [new Block("Genesis")];
    }
}

module.exports = Blockchain;

点击运行。

4: Adding Blocks

查看要求：

输入：

const Block = require('./Block');

class Blockchain {
    constructor() {
        this.chain = [new Block("Genesis")];
    }

    addBlock(block) {
        this.chain.push(block);
    }
}

module.exports = Blockchain;

点击运行。

5: Linking The Blocks

查看要求：

这里需要改两个文件，首先是

输入：

const Block = require('./Block');

class Blockchain {
    constructor() {
        this.chain = [new Block("Genesis")];
    }

    addBlock(block) {
        block.previousHash = this.chain[this.chain.length - 1].toHash();
        this.chain.push(block);
    }
}

module.exports = Blockchain;

然后改这个：

const SHA256 = require('crypto-js/sha256');

class Block {
    constructor(data) {
        this.data = data;
    }
    toHash() {
        if (this.previousHash) {
            return SHA256(this.data.toString() + this.previousHash.toString());
        } else {
            return SHA256(this.data.toString());
        }
    }
}

module.exports = Block;

点击运行。

6: Validating the Chain

查看要求：

输入：

const Block = require('./Block');

class Blockchain {
    constructor() {
        this.chain = [new Block("Genesis")];
    }

    addBlock(block) {
        block.previousHash = this.chain[this.chain.length - 1].toHash();
        this.chain.push(block);
    }

    isValid() {
        for (let i = 0; i < this.chain.length; i++) {
            if ((i + 1) >= this.chain.length) {
                break;
            }
            if (this.chain[i].toHash().toString() !== this.chain[i+1].previousHash.toString()) {
                return false;
            }
        }
        return true;
    }
}

module.exports = Blockchain;

点击运行。

以上第四周的教程学习完成。

未完待续……

了解更多，请关注作者：https://twitter.com/bitc2024

const { sha256 } = require("ethereum-cryptography/sha256"); const { toHex, utf8ToBytes } = require("ethereum-cryptography/utils"); // the possible colors that the hash could represent const COLORS = ['red', 'green', 'blue', 'yellow', 'pink', 'orange']; // given a hash, return the color that created the hash function findColor(hash) { hex = toHex(hash); for(let i = 0; i < COLORS.length; i++) { b = utf8ToBytes(COLORS[i]); h = sha256(b); if (toHex(h) === hex) { return COLORS[i]; } } } module.exports = findColor;

const { keccak256 } = require("ethereum-cryptography/keccak"); const { utf8ToBytes } = require("ethereum-cryptography/utils"); function hashMessage(message) { return keccak256(utf8ToBytes(message)); } module.exports = hashMessage;

const secp = require("ethereum-cryptography/secp256k1"); const hashMessage = require('./hashMessage'); const PRIVATE_KEY = "6b911fd37cdf5c81d4c0adb1ab7fa822ed253ab0ad9aa18d77257c88b29b718e"; async function signMessage(msg) { return secp.sign(hashMessage(msg), PRIVATE_KEY, { recovered : true}); } module.exports = signMessage;

const secp = require("ethereum-cryptography/secp256k1"); const hashMessage = require("./hashMessage"); async function recoverKey(message, signature, recoveryBit) { return secp.recoverPublicKey(hashMessage(message), signature, recoveryBit); } module.exports = recoverKey;

const secp = require("ethereum-cryptography/secp256k1"); const { keccak256 } = require("ethereum-cryptography/keccak"); function getAddress(publicKey) { return keccak256(publicKey.slice(1)).slice(-20); } module.exports = getAddress;

const SHA256 = require('crypto-js/sha256'); const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff); const MAX_TRANSACTIONS = 10; const mempool = []; const blocks = []; function addTransaction(transaction) { mempool.push(transaction); } function mine() { } module.exports = { TARGET_DIFFICULTY, MAX_TRANSACTIONS, addTransaction, mine, blocks, mempool };

const SHA256 = require('crypto-js/sha256'); const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff); const MAX_TRANSACTIONS = 10; const mempool = []; const blocks = []; function addTransaction(transaction) { mempool.push(transaction); } function mine() { let block = {id:blocks.length}; blocks.push(block); } module.exports = { TARGET_DIFFICULTY, MAX_TRANSACTIONS, addTransaction, mine, blocks, mempool };

const SHA256 = require('crypto-js/sha256'); const TARGET_DIFFICULTY = BigInt(0x0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff); const MAX_TRANSACTIONS = 10; const mempool = []; const blocks = []; function addTransaction(transaction) { mempool.push(transaction); } function mine() { let block = {id:blocks.length}; block.hash = SHA256(JSON.stringify(block)); blocks.push(block); } module.exports = { TARGET_DIFFICULTY, MAX_TRANSACTIONS, addTransaction, mine, blocks, mempool };

const SHA256 = require('crypto-js/sha256'); class Block { constructor(data) { this.data = data; } toHash() { return SHA256(this.data.toString()); } } module.exports = Block;

const Block = require('./Block'); class Blockchain { constructor() { this.chain = [new Block("Genesis")]; } addBlock(block) { this.chain.push(block); } } module.exports = Blockchain;

const SHA256 = require('crypto-js/sha256'); class Block { constructor(data) { this.data = data; } toHash() { if (this.previousHash) { return SHA256(this.data.toString() + this.previousHash.toString()); } else { return SHA256(this.data.toString()); } } } module.exports = Block;

const Block = require('./Block'); class Blockchain { constructor() { this.chain = [new Block("Genesis")]; } addBlock(block) { block.previousHash = this.chain[this.chain.length - 1].toHash(); this.chain.push(block); } isValid() { for (let i = 0; i < this.chain.length; i++) { if ((i + 1) >= this.chain.length) { break; } if (this.chain[i].toHash().toString() !== this.chain[i+1].previousHash.toString()) { return false; } } return true; } } module.exports = Blockchain;

andrecronje

More from andrecronje

andrecronje

More from andrecronje

No activity yet

More from andrecronje

andrecronje

andrecronje

No activity yet

More from andrecronje

Alchemy University 学习教程，Blockchain Cryptography

Alchemy University 学习教程，Blockchain Cryptography

No activity yet

No activity yet

The First Primitive

Cryptographic Hashes

Digital Signatures

Public Key Exercise

Proof of Work

Proof of Work Miner

Blockchain Network

Blockchain Data Structure

The First Primitive

Cryptographic Hashes

Digital Signatures

Public Key Exercise

Proof of Work

Proof of Work Miner

Blockchain Network

Blockchain Data Structure