none): no Attestation Statement is provided
basic): Authenticator’s attestation key pair is specific to an authenticator model.
self): Authenticators that have no specific attestation key use the credential private key to create the attestation signature
AttCA): Authenticators are based on a Trusted Platform Module (TPM). They can generate multiple attestation identity key pairs (AIK) and requests an Attestation CA to issue an AIK certificate for each.
AnonCA): Authenticators use an Anonymization CA, which dynamically generates per-credential attestation certificates such that the attestation statements presented to Relying Parties do not provide uniquely identifiable information.
ECDAA): Authenticator receives direct anonymous attestation (DAA) credentials from a single DAA-Issuer. These DAA credentials are used along with blinding to sign the attested credential data.