It's far from bullet proof, because if macros are disabled the code won't run.

I found a macro that hides all sheets as the file closes. With macros
disabled, all one would see is a cover sheet. I will look over your
suggestion later today. Thanks

why not make the workbook password protected and make sure that the user
knows the password?

There is nothing stopping a person from giving the workbook & password
to 100 people.