Create new UDC data connection with windows service user account

Question

About a month ago we had a MOSS RAP meeting with MS Sharepoint Experts, they recommende us to use service user account to run the Sharepoint instances and our custom services too. We did it and it works well.

We have a major security issue inside the Infopath forms, because we uses SQL authentication with non-encrypted way to receive some informations from our custom database. They said, use the service account to authenticate to the database with the service user and windows authentication method.

I created a new UDC connection, but it is not clear for me, beacause I need to set the authentication details too such as username and password. Here is the UDC authentication code snippet.

    <udc:Authentication>
        <udc:UseExplicit CredentialType="NTLM">
            <udc:UserId>my_service_user</udc:UserId>
            <udc:Password>myServiceUserPassword</udc:Password>
        </udc:UseExplicit>
    </udc:Authentication>

Is it possible to use the UDC with service user without credentials? (I tried to comment the authentication attributes and it causes error, inside the event viewer I saw an anonymous logon error).

Thank you for your help!