In Small Business Edition, you must use NTFS rights on the qvw files.
in Entreprise Edition, you can use DMS security and use an authorisation tab.
In addition, it is possible to use a section access (in the application script) to have security on the data. A user, who isn't mentionned in the section access won't see it in the access point.
Assuming you are using Windows server. If so, put these applications in different folders in the server. Then use the windows folder security feature (Right click on folder->Properties->Security tab ...) to restrict the access to specific users. Have a look at this discussion
