A big caveat, though: Although hardware security keys and the Advanced Data Protection program lock down your account better, they also mean Apple can't help you recover access.

"This feature is designed for users who, often due to their public profile, face concerted threats to their online accounts, such as celebrities, journalists, and members of government," Apple said in a statement.

"This takes our two-factor authentication even further, preventing even an advanced attacker from obtaining a user's second factor in a phishing scam."

Hardware security keys have been around for years, but the Fast Identity Online, or FIDO, group has helped standardize the technology and integrate its use with websites and apps.

Google, Microsoft, Apple and other allies are also working to support a different FIDO authentication technology called passkeys.

Passkeys are designed to replace passwords altogether, and they don't require hardware security keys.