Key Derivation

Overview

KeyApp uses a unified key derivation strategy based on standard BIP protocols where applicable, while respecting chain-specific requirements.

Master Seed

The root of all keys is a 12 or 24 word mnemonic phrase (BIP-39). This mnemonic is converted into a binary seed which is then used to derive chain-specific keys.

Note: For BioForest chains, the mnemonic string itself (UTF-8 encoded) acts as the seed for Ed25519 key generation, rather than the BIP-39 binary seed. This is a legacy compatibility requirement.

Derivation Paths

Chain Kind	Algorithm	Path / Method	Standard
BioForest	Ed25519	sha256(mnemonic)	Custom
Bitcoin	Secp256k1	m/84'/0'/0'/0/0	BIP-84 (Native SegWit)
Ethereum	Secp256k1	m/44'/60'/0'/0/0	BIP-44
Tron	Secp256k1	m/44'/195'/0'/0/0	BIP-44

Implementation

Unified Interface

Address derivation is exposed via the IIdentityService interface implemented by each chain adapter.

interface IIdentityService {
  deriveAddress(seed: Uint8Array, index?: number): Promise<string>;
  deriveAddresses(seed: Uint8Array, startIndex: number, count: number): Promise<string[]>;
}

Usage

The helper function deriveWalletChainAddresses acts as the single entry point for deriving addresses for a user's wallet across multiple selected chains.

// src/services/chain-adapter/derive-wallet-chain-addresses.ts
export async function deriveWalletChainAddresses(params) {
  // Iterates through selected chains and calls provider.deriveAddress
}

Specific Implementations

• BioForest (BioforestIdentityService):

  • Uses createBioforestKeypair(seedString).
  • Same keypair for all indices (no HD support yet).

• Bitcoin (BitcoinIdentityService):

  • Uses deriveBitcoinKey(mnemonic, 84, index).
  • Supports full HD derivation.

Security Considerations

• Memory: Mnemonics are kept in memory only during the derivation process and cleared immediately after.
• Storage: Keys are never stored in plain text. See Wallet Storage for encryption details.