For ZTA, what should be used to validate the identity of an entity?

Multifactor authentication is a method of validating the identity of an entity by requiring two or more factors, such as something the entity knows (e.g., password, PIN), something the entity has (e.g., token, smart card), or something the entity is (e.g., biometric, behavioral). Multifactor authentication enhances the security of Zero Trust Architecture (ZTA) by reducing the risk of identity compromise and unauthorized access.

References = Certificate of Competence in Zero Trust (CCZT) - Cloud Security Alliance, Zero Trust Training (ZTT) - Module 4: Identity and Access Management