# Hybrid Identity Authentication & Entra Connect

Hybrid identity model & directory synchronisation is the most common for enterprise users

- Directory synchronisation allows updates to AD DS to synchronise with the Entra ID
- AD DS identities are synchronised with Microsoft 365 and users are managed on-prem

#### Managed Authentication

##### Password Hash Synchronisation (PHS) (Recommended)

Entra ID handles authentication using a locally hashed password

- Password hashes are synchronised out from AD DS to Entra ID so that users have the same password

[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/eE1image.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/eE1image.png)


[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/U1uimage.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/U1uimage.png)


##### Pass-Through Authentication (PTA)

Entra ID sends the credentials to an on-prem software agent to be authenticated by AD DS

[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/Pgjimage.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/Pgjimage.png)


[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/OW7image.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/OW7image.png)

#### Federated Authentication

Federated Authentication - Entra ID redirects the client's authentication request to another identity provider

- Primarily for large enterprises with more complex requirements
- Users have the same password on-prem and in the cloud and do not have to sign in again to use 365
- Supports additional requirements such as smartcards or third party MFA

[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/Hcximage.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/Hcximage.png)

[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/2Zqimage.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/2Zqimage.png)