Kids created by these wallets will not be hardened
They’re m/44'|49'|84'/0'/0' for trezor one/T and m/49'|84'/0'/0' for ledger X/S. All subsequent kids aren’t hardened.
If an xpub is leaked for a mnemonic phrase + passphrase, you probably have
any of the kids’s non-public keys, you may compromise your complete
pockets linked to the xpub and all different kids, hardened or
non-hardened BUT the attacker will be unable to compromise every other
meomonic phrase + paassphrase you could have because it has a distinct xpub, and
in the end totally different kids
That is the reason from bip32: “data of a father or mother prolonged public key plus any non-hardened non-public key descending from it’s equal to understanding the father or mother prolonged non-public key (and thus each non-public and public key descending from it). Because of this prolonged public keys have to be handled extra rigorously than common public keys.”
I wish to know the way it’s even attainable to leak a childs non-public key on
a trezor or a ledger as not one of the outputs are in a position to leak these
Personal keys ought to by no means go away {hardware} wallets with none extraordinary trigger. Often, solely the grasp seed is transferable as a chance from a {hardware} pockets gadget. And there will not be many causes to take action. If an attacker is ready to backdoor your gadget and steal keys, the very fact of sharing xpubs can be irrelevant.