Examples described herein relate to an authentication management system and a method for managing authentication of a user between an enterprise-level authentication protocol and a cloud-native authentication protocol. The authentication management system may receive an authentication request from an application hosted on a private on-premise network to authenticate a user using the enterprise-level authentication protocol. The authentication request is generated by the application upon receiving an access request from the user via a software as-a-service (SaaS) cloud platform in a cloud-native authentication protocol. Further, the authentication management system may generate an authentication response compliant with the enterprise-level authentication protocol based on an authentication reply that is formatted in compliance to the cloud-native authentication protocol and received from a cloud-native identity and authentication management system based on the authentication request. The authentication management system may then send the authentication response to the application.