At AAL3, at least one of the authenticators must be a cryptographic hardware-based authenticator. WPA2/EAP Authenticators, RADIUS client, EAP server, and RADIUS authentication server. Examples of cryptographic authenticators include OATH authenticators and FIDO authenticators. MLB postseason games will have three or more authenticators. NIST defines three levels of assurance with respect to authenticators. MLB employs approximately 150 authenticators, with four being appointed to each team. The subscriber will be tasked with maintaining the authenticators. The following sections describe narrow classes of authenticators. Concrete examples of FIDO2 platform authenticators include Windows Hello and the Android operating system. Relevant examples of platform authenticators include Windows Hello and the Android operating system. These Sealed Authenticators are stored in a safe which has two separate locks. Authenticators may be characterized in terms of secrets, factors, and physical forms.