Az - PTA - Pass-through Authentication

👉 Overview

👀 What ?

Azure Pass-Through Authentication (PTA) is a method for Microsoft Azure Active Directory to validate user passwords directly against the on-premises Active Directory. It is designed to allow users to access both on-premises and cloud-based applications using the same credentials.

🧐 Why ?

PTA is important because it simplifies the user experience by providing a seamless sign-in process. It eliminates the need for password synchronization or the use of federation services, reducing the risk of password-related security issues. Businesses transitioning to cloud services should pay attention to PTA as it can help them manage user identities more effectively and securely.

⛏️ How ?

To implement PTA, you need to install and configure Azure AD Connect, a tool provided by Microsoft. This tool synchronizes your on-premises Active Directory with Azure AD. Then, you need to enable PTA in the Azure portal by selecting 'Pass-through Authentication' as your sign-in method. The final step is to install the PTA Agent on your on-premises servers to handle authentication requests.

⏳ When ?

Microsoft introduced PTA in 2017 as a part of their efforts to enhance the security and usability of their cloud services.

⚙️ Technical Explanations

When a user attempts to sign in, Azure AD sends the username and password to a PTA Agent located in the on-premises environment. The PTA Agent then validates the credentials against the on-premises Active Directory and returns the result to Azure AD. This entire process is secured using HTTPS to prevent eavesdropping or tampering. The advantage of this method is that it doesn't require storing hashed passwords in the cloud or maintaining federation infrastructure, making it a simpler and potentially safer option for businesses.