> The trick WebAuthn/U2F do is equivalent to if somehow, magically, the device could have an effectively infinite number of private keys, not just one, or one p

> The trick WebAuthn/U2F do is equivalent to if somehow, magically, the device could have an effectively infinite number of private keys, not just one, or one per site, but one for every enrollment on a site. Ledger Nano S (a hw crypto wallet) has a virtually infinite number of public/private key pairs. In fact, all hardware wallets that implement "hierarchical deterministic wallets" have them. All the wallet needs to determine a private key for one of its public keys is the "derivation path" of that pair. Even more interesting, if one site knows one of your public keys, it can't determine the rest of them without knowing your "master public key".