This can be done as described below.
- Log in to the Domain Controller machine.
- Open the Group policy object editor( see How to open group policy object editor in Server 2003)
- Go to the node Computer Configuration -> Administrative Templates -> Network -> Offline files
- Now the right side pane shows a list of settings related to offline files feature. Among these select “Encrypt the offline files cache” by double click and it will open a window like below.
- Here select the box “Enabled” to encrypt the local cache created by offline files.
- Click on Apply and close the windows.
The above steps enable encryption for all the computers that are part of a domain.
To enable offline files encryption on a single computer we can follow the below steps on Windows XP.
- Open Offline Files tab( My computer->Tools->Folder Options )
- Select the check box “Encrypt offline files to secure data“
- Click Apply and OK
- Close Folder Options window
We can enable offline files encryption on a system by modifying registry settings too. You need to set the data of the registry value EncryptCache under the below path to 1 to enable offline files encryption.