Derive Child Key from Parent

WHAT IT DOES

Derive Child Key from Parent enables you to derive child keys from BIP32 extended parent keys (xpub/xprv). BIP32 (Hierarchical Deterministic Wallets) allows the derivation of child keys from a parent key using a derivation index and a hardened flag. This tool takes a parent key (extended public or private key), a child index, and a hardened flag, and derives the corresponding child key. This is essential for developers, auditors, and users working with HD wallets, multi-account setups, and key derivation in blockchain applications. The tool provides clear output showing the parent key, child index, hardened status, and the derived child key.

HOW TO USE

Connect your wallet using the BGWallet connector (required for context). Enter a parent key in the input field—this must be an extended public key (xpub) or extended private key (xprv). Enter the child index (a non-negative integer). Select whether the derivation should be hardened or non-hardened. Click "Derive Child Key" to compute the child key. The tool displays the parent key (masked), the child index, hardened status, and the derived child key. You can copy the child key to your clipboard for use. The result includes a detailed breakdown showing the parent key, child index, and derived child key.

TECHNICAL MECHANISM

This tool implements BIP32 child key derivation. The derivation process: (1) the parent key is validated as an extended key (xpub or xprv); (2) for non-hardened derivation, the public key and chain code are used; (3) for hardened derivation, the private key and chain code are used; (4) the HMAC-SHA512 of the appropriate data is computed to generate the child key and chain code; (5) the child key is returned as an extended key. The tool provides a simplified derivation for demonstration. All computation is performed locally in the browser with no data sent to external servers.

WHAT IT CANNOT SEE

This tool cannot verify that the derived child key corresponds to an actual wallet with funds or on-chain activity—it only performs key derivation. It does not support derivation for non-BIP32 chains; only BIP32-style keys are supported. The tool cannot detect if the parent key is compromised or known to be malicious. It does not support hardware wallet or secure enclave key derivation. The tool cannot guarantee that the derived key is safe to use based solely on the parent key format. It does not support non-standard derivation schemes or custom paths beyond standard BIP32. The tool cannot recover the parent key from the child key; the derivation is one-way. It does not support key derivation with custom entropy or salts.

PLEASE NOTE

This tool is designed for developers and users working with BIP32 HD wallets. Extended keys start with xpub (public) or xprv (private). Child indices range from 0 to 2^31-1. Hardened derivation uses the private key for derivation, providing additional security. Non-hardened derivation uses the public key, allowing public key derivation without the private key. The tool provides a simplified derivation for educational and testing purposes. Always verify the derived key through trusted sources before using it in transactions. The tool is read-only and does not require any on-chain interactions. The derivation is performed locally in the browser and is never transmitted to external servers.