src/ecc/key_private.js
function getChildKey(name) {
        // console.error('WARNING: getChildKey untested against evtd'); // no evtd impl yet
        const index = createHash("sha256").update(toBuffer()).update(name).digest();
        return PrivateKey(index);
    }
function getChildKey(name) {
        // console.error('WARNING: getChildKey untested against evtd'); // no evtd impl yet
        const index = createHash("sha256").update(toBuffer()).update(name).digest();
        return PrivateKey(index);
    }
/** ECIES TODO unit test @arg {string|Object} pubkey wif, PublicKey object @return {Buffer} 64 byte shared secret  function getSharedSecret(public_key) { public_key = PublicKey(public_key).toUncompressed() var P = public_key.Q.multiply( d ); var S = P.affineX.toBuffer({size: 32}); // ECIES, adds an extra sha512 return hash.sha512(S); } 
@arg {string} name - child key name.
@return {PrivateKey}

@example activePrivate = masterPrivate.getChildKey('owner').getChildKey('active')
@example activePrivate.getChildKey('mycontract').getChildKey('myperm')