Distributing Safe Demo Apps

[John Phelan-Cummings]

I am about to distribute demos of an upcoming Beta 2 of my
software in order to get the interest of a much larger
audience into becoming testers. It is a split database
with over two hundred tables.

I am looking for ways to distribute a full version.
Therefore, my thinking is that it should be "time-limit".
Otherwise, I might as well give it away. A software
company that has a distribution program that I am thinking
of using, does not include this feature. However, people
will be unable to unzip my files in order to install my
application separately.

They tell me that developers usually "hard-code" the kind
of security that I am looking for, into their application.

Has anyone heard of doing this, or, how to do it?

John

 

[RICHARD BROMBERG]

John

By coincidence I am working on a similar problem.
Here is a method I just implimented. I am still testing it anw would
appreciate any comments.

On the opening form or switchboard hard code the following :

Private Sub Form_Activate()
Dim TodayDate, CutoffDate As Date
CutoffDate = "09/21/2003" ' Program will not run
after this date
TodayDate = Date
If CutoffDate > TodayDate Then
MsgBox("The Trial Period has Expired") ' or any other warning
message
DoCmd.Quit
End If
End Sub

Put the same code into the Form_Open() and/or Form_Load() .

So far so good,
Now to protect someone from unzipping or reverse engineering your program
you should distribute the program as an MDE file.

With the program open and running , Click Tools | Database Utilities |
Make MDE File .

 

[Guest]

Along the date lines...

I've also heard a technique to store the first date of opening the database
as well as the current date of each subsequent opening. Check if the
current date is past "x" number of days when opening and if past "x" days,
tell the user "Time's Up!"

If the "current date" is ever less than the stored "current date" the
assumption is the clock has been set back... blow up!

Steve

 

[TC]

And of course, all of the stored dates & other information can be encrypted,
so the user can not make any sense of them, even if he can see them in the
registry (or where-ever). And they can be checksummed, so the system will
know if the user has altered them. And there are other techniques to tell if
the user saved the original values, then copied them back at a later time in
an effort to revive the system!

TC