##### To enable mutual authentication for all applications

The Application Server uses the `certificate` realm for HTTPS authentication.

1. Expand the Configurations node.
2. In the Cluster and Enterprise profile, select the instance to configure:
   - To configure a particular instance, expand the instance’s config node. For example, the default instance, `server`, expand the `server-config` node.
   - To configure the default settings for all instances, expand the `default-config` node.
3. Expand the Security node.
4. Expand the Realms node.
5. Select the `certificate` realm.
6. Click the Add Property button.
   1. In the Name field, enter `clientAuth`.
   2. In the Value field, enter `true`.
7. Click Save.
8. Restart the Application Server if Restart Required displays in the console.

   After restarting the server, client authentication is required for all applications that use the `certificate` realm.