Understanding Password Synchronization Methods: Password-Through vs. Password Hash Synchronization
In today’s hybrid IT environments, where both on-premises and cloud services are used, managing user authentication securely and reliably is essential. Two common methods of syncing passwords from on-prem Active Directory (AD) to Azure Active Directory (Azure AD) are Password-Through Synchronization (also known as Pass-through Authentication) and Password Hash Synchronization.
This article breaks down the difference between the two in simple terms and explains what happens when your AD server goes down.
🟦 What Is Password-Through Synchronization?
Password-through synchronization means that when a user logs into a cloud service like Microsoft 365, Azure AD checks the password by contacting your on-premises AD in real-time.
✅ Pros:
❌ Cons:
🟩 What Is Password Hash Synchronization?
Password hash synchronization works differently. It copies a scrambled version (hash) of the password from your on-prem AD to Azure AD.
✅ Pros:
❌ Cons:
🧠 Final Thoughts
Choosing between password-through and password-hash synchronization depends on your organization’s needs:
For many, a hybrid setup using both methods (with password hash sync as a backup to pass-through) gives the best of both worlds.