How is the IIS Integrated External Authentication conducted?

The process of IIS Integrated External Authentication involves the PVWA (Password Vault Web Access) acting as an intermediary in the authentication process. When a user attempts to authenticate, the PVWA collects the credentials and securely sends them to the IIS service hosted on the external server. The IIS service then handles the task of confirming the user's credentials, checking them against the appropriate authentication mechanisms.

This method is secure as it keeps the authentication process centralized through the IIS service, leveraging existing infrastructure for user validation without exposing sensitive information directly to the user. It also allows for a streamlined process where authentication can be managed consistently and efficiently through the web application. In this way, the PVWA serves as a critical component in coordinating the authentication without storing or directly transmitting the credentials inappropriately.

Other choices either suggest a less secure method of handling credentials that could expose sensitive data or imply a less integrated approach that doesn't align with best practices for security and efficiency in authentication systems.