A Hierarchical Deterministic Wallet represents a large tree of private keys, which can be reproduced from an initial seed. Each node in the tree is represented by an HDNode which can be branched.

This is an implementation of a hierarchical wallet (HD wallet) for Ethereum in JavaScript using the Ethers.js library. The wallet will hold a BIP39 mnemonic phrase and will allow deriving private keys and addresses from it. The concept of hierarchical wallets (HD Wallets) is based on BIP39 and BIP44 specs. The HDNode class in the Ethers.js library holds a seed key + the ability to derive private keys by a certain derivation path.

• Initialize a package.json

npm init -y

• ethers.js

npm install --save ethers

Play a bit with the BIP39 online implementation here: iancoleman. Generate/load mnemonics, derive Ethereum and Bitcoin keys and addresses.

1. Restore an HD node by given existing mnemonic words:

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To create an HD node from a mnemonic, use ethers.utils.HDNode.fromMnemonic. The HD node stores a key pair (publicKeyBytes has been truncated).

2. When an ethers.Wallet instance is created from a mnemonic, it actually uses HDNode.fromMnemonic, derives once, and from the new HD node, it takes the private key to build the wallet.

1. Generate a new random HD node (generate random mnemonics). To create a random HD node, you can either do ethers.Wallet.createRandom and build the HD node from the mnemonic, or you can build the mnemonic from 16 bytes of entropy using ethers.utils.HDNode.entropyToMnemonic.

2. Create a random HD wallet using ethers.Wallet.createRandom.

Encrypt and save given HD node to a JSON document by password. To save the HD Wallet in an encrypted JSON format, you need the Wallet to include the mnemonic phrase. The mnemonic is encrypted in the x-ethers part of the json.

Decrypt and load an HD node from a JSON document using a password. Use ethers.Wallet.fromEncryptedJson(json, password).

Derive keys (and their associated addresses) from HD Wallet by given derivation path. Derivation path is m/44'/60'/0'/0.

Take the second of the derived wallets (wallets[1]) and sign a transaction with a given recipient address and ether value.

• Ethereum Recipient Address

0x933b946c4fec43372c5580096408d25b3c7936c5 

MI2: Module 3: E1