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Seed Phrase Generation ​

Process and functions involved in generating and deriving cryptographic seeds from mnemonic phrases within the Non-Custodial Application. Seed phrases are a critical component of hierarchical deterministic (HD) wallets, providing a human-readable backup for cryptographic keys.

1. Introduction to Seed Phrases ​

A seed phrase (or mnemonic phrase) is a sequence of 12 words that serves as a master key for a cryptocurrency wallet. It is generated using a standardized algorithm BIP-39 and can be used to deterministically derive all private keys and addresses within a wallet. This makes it the single most important piece of information for recovering or backing up a wallet.

In this application, the seed phrase is generated and then used to derive a cryptographic seed, which is subsequently used to initialize the hardware security card.

2. Core Functions ​

The seed phrase generation and derivation process relies on two primary functions:

generateMnemonic() ​

This function is responsible for creating a new, random mnemonic phrase.

  • Description: Generates a new 12-word mnemonic phrase according to the BIP-39 standard. The words are selected from a predefined wordlist.
  • Parameters: None.
  • Returns: string[] - An array of 12 words, representing the mnemonic phrase.
  • Usage: This function should be called when a new wallet is being set up or a new card is being registered, requiring a fresh seed.

deriveSeedFromMnemonic(mnemonicString) ​

This function takes a mnemonic phrase and converts it into a cryptographic seed.

  • Description: Derives a 512-bit (64-byte) cryptographic seed from a given mnemonic phrase string. This process typically involves a key derivation function like PBKDF2, using the mnemonic as the password and a fixed salt.
  • Parameters:
    • mnemonicString: string - The space-separated 12-word mnemonic phrase.
  • Returns: Uint8Array - A Uint8Array containing the 64-byte derived seed.
  • Usage: The derived seed is then used to initialize the hardware security card, ensuring that the card's keys are deterministically linked to the user's seed phrase.

3. Usage Example ​

Here’s how you would typically use these functions to generate a seed phrase and derive a master key for a new card registration process.

javascript
// Assuming '@/api/mnemonic' contains the generateMnemonic and deriveSeedFromMnemonic functions

import { generateMnemonic, deriveSeedFromMnemonic } from '@/api/mnemonic';

// 1. Generate a new 12-word mnemonic phrase
const seedPhrasesArray = generateMnemonic();
console.log('Generated Mnemonic Phrase:', seedPhrasesArray.join(' '));
// Example output: "word1 word2 word3 word4 word5 word6 word7 word8 word9 word10 word11 word12"

// 2. Join the array of words into a single space-separated string
const seedPhrasesString = seedPhrasesArray.join(' ');

// 3. Derive the cryptographic seed from the mnemonic string
const derivedSeed = deriveSeedFromMnemonic(seedPhrasesString);
console.log('Derived Seed (Uint8Array):', derivedSeed);
// Example output: Uint8Array(64) [123, 45, 67, ..., 89] (a 64-byte array)