When working with Azure Active Directory and looking at different password sync technologies, two generally come up in Azure AD Connect configurations: Password Hash Synchronization and Pass-Through Authentication. Since these affect how authentication happens with Azure Active Directory (Azure AD), understanding their functions, differences, and usage helps to choose the right technology for the job and requirements with cloud authentication and single sign-on, which most want to take advantage of when migrating to cloud SaaS.
Password Hash Synchronization
Password Hash Synchronization (PHS) is a method for synchronizing user passwords from an on-premises Active Directory to Azure AD. The password hash sync process involves the synchronization of password hashes, rendering it a favored authentication method for various organizations. This method allows users to leverage the same username and password for cloud services and on-premises resources.
Credits: Microsoft Tech Community
Benefits of Password Hash Synchronization
The password hash sync method provides several advantages. It simplifies the user sign-in process, adheres to password policies on-premises, and offers a seamless sign-in experience. Additionally, it supports features like leaked credentials protection, ensuring heightened security.
Pass-Through Authentication
The Pass-through authentication (PTA) sign-in method works differently. Pass-through authentication agents are installed on on-premises domain controllers and receive authentication requests from M365 logins. They validate the login request against the on-premises Active Directory. This allows users to sign into Azure AD with their corporate credentials without password hashes stored in the cloud.
Credits: Microsoft Tech Community
Why Choose Pass-Through Authentication
Pass-through authentication offers real-time user sign-in validation and other benefits from a security perspective. These include supporting on-premises sign-in features like sign-in hour policies and offering a seamless SSO experience. It’s especially ideal when organizations have requirements preventing password hashes from synchronizing to the cloud.
Comparing Authentication Methods
Let’s compare a few characteristics of the solutions and which options are available with each one.
Security Considerations
Security remains one of the primary focuses of organizations considering Password Hash Synchronization and Pass-Through Authentication. Both methods have security benefits, with PHS providing leaked credential protection and PTA ensuring passwords remain on-premises.
>User Experience: Smooth Sign-Ins
Handling Expired Passwords in Pass-Through AuthenticationIn contrast, Pass-Through Authentication handles expired passwords somewhat differently. Since it validates user credentials in real-time against on-premises domain controllers, the process is immediate and dynamic.
Users are prompted to update their credentials when a password expires during their next sign-in attempt. The updated password instantly applies to both on-premises and cloud services access without waiting for synchronization cycles. This approach offers a more immediate and synchronized response to password changes and expiry events.
Account Lockout in Password Hash Synchronization (PHS)
With Password Hash Synchronization, account lockout policies are primarily enforced at the Azure AD level. When a user repeatedly attempts to sign in with incorrect credentials, Azure AD tracks these attempts. Once the threshold for unsuccessful attempts is reached, an account locked event happens in Azure AD based on its defined lockout policies.
It’s important to note that this does not necessarily lock the user out of the on-premises Active Directory account; instead, it prevents access to Azure AD and its associated resources. For security practices to be aligned, organizations must ensure that the lockout policies in Azure AD match with those set in the on-premises Active Directory Domain Services (AD DS) environment to be consistent.
Account Lockout in Pass-Through Authentication (PTA)
In contrast, Pass-Through Authentication handles account lockouts differently. Since PTA authenticates users in real-time against the on-premises Active Directory, the lockout policies established there are the ones enforced. If a user enters incorrect credentials too often, the account is locked out per the on-premises Active Directory’s policy, locking them out of both on-premises and cloud-based resource access.
This approach offers a unified lockout policy enforcement mechanism, as the on-premises Active Directory is the authoritative source for user authentication. It ensures consistency in access control and security practices across all resources, irrespective of their location.
Password writeback
Password writeback is an important feature designed to enhance the synchronization between on-premises Active Directories and Azure AD. With this functionality enabled, any changes to user passwords within the Azure AD environment are automatically synchronized to the on-premises Active Directory.
Below, you can see the password writeback option configured in Azure AD Connect.
This two-way synchronization mechanism ensures consistency in user credentials across different environments, allowing users to have a single, unified password for accessing both cloud-based and on-premises resources.
When organizations are in a hybrid configuration, it simplifies the management of user credentials while allowing admins to maintain a secure and synchronized access control environment.
Achieving a Hybrid Identity with Azure AD
Azure AD Connect integrates on-premises directories with Azure AD, providing a consistent and secure user experience. This tool is crucial for implementing a hybrid identity solution, and it supports both PHS and PTA as authentication methods.
Azure AD’s Multi-Faceted Authentication Methods
Azure AD offers various authentication options, allowing organizations to select methods that best fit their needs, such as Password Hash Synchronization, Pass-Through Authentication, or Active Directory Federation Services (AD FS).
Frequently Asked Questions
How do Hybrid Identity Solutions Integrate with Azure AD Connect?
Azure AD Connect integrates your on-premises Active Directory with Azure AD. It supports both Password Hash Synchronization and Pass-Through Authentication, providing a consistent user sign-in experience while adhering to your selected authentication method.
Can Pass-Through Authentication Agents Work Behind a Proxy?
Yes, Pass-Through Authentication Agents can function behind a proxy. It’s important to make sure that the necessary URLs are accessible for the agents to communicate effectively with Azure AD. Adequate planning and configuration are required to implement this setup successfully.
What Happens During Temporary Loss of Connection with PTA Agents?
During a temporary loss of connection with PTA agents, users may face challenges in signing in to cloud resources. To mitigate this risk, deploying multiple agents is advisable. This approach provides high availability and facilitates load balancing among the authentication requests, ensuring continuous accessibility even if one agent is temporarily unreachable.
How Frequently Does Password Hash Synchronization Occur?
By default, Azure AD Connect synchronizes password hashes every 30 minutes. However, this interval can be configured to meet the specific needs of your organization’s environment and requirements.
Is Multi-Factor Authentication Supported with Both Methods?
Password Hash Synchronization and Pass-Through Authentication support Multi-Factor Authentication (MFA). Using MFA adds a layer of security, verifying the user’s identity by requiring multiple verification forms before granting access.
Wrapping up
Understanding the differences between password hash synchronization and pass through authentication is important as each has its own pros and cons to be aware of. Password hash synchronization is generally the more adopted solution of the two. However, pass-through authentication certainly has its own benefits, especially for organizations that are prevented from synchronizing and storing password hashes in the cloud. Regardless of the one chosen, both methods are secure and can allow users to have a seamless login experience.
Related Posts:
Microsoft 365 for Beginners – Password Hash Synchronization with Microsoft 365: A Comprehensive Guide – Part 29
Microsoft 365 for Beginners – Business Standard vs Premium Plans – Part 32
Follow our Twitter and Facebook feeds for new releases, updates, insightful posts and more.
