COM Addin Security
 

Hi,

I am planning to distribute a COM Addin (*.DLL) for excel that has
some proprietary functions. Is there a better way to prevent a group
users from using the functions inside the DLL? Right now I have a
private variable that is set to "valid" if the user meets certain
criteria and "invalid" otherwise in the OnConnection procedure. Each
function then checks for the validity and returns garbage if invalid.
This adds considerable overhead to the functions. I am looking for a
quick way to do this without adding too much overhead.

Thanks,
Sridhar.