AuthenticatorAttachment

Platform attachment The respective authenticator is attached using platform-specific transports.

Usually, authenticators of this class are non-removable from the platform. A public key credential bound to a platform authenticator is called a platform credential.

Cross-platform attachment The respective authenticator is attached using cross-platform transports. Authenticators of this class are removable from, and can "roam" among, client platforms. A public key credential bound to a roaming authenticator is called a roaming credential.