Trial Version

Posted on 2005-02-28
Medium Priority
Last Modified: 2010-04-05
I  have an app which I want to provide a trial version of. Although a bit rudimemtary, I think the best way would be to check the date of a file which is modified on installation and check periodically wether the date since the modification of this file is 28 days or more. If so the app will not run.
Any I deas on the best way to achieve this?
As a side line is it OK to have Delphi 6 and 2005 on the same machine?
Question by:lloydie-t
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LVL 10

Expert Comment

ID: 13423240
Hi, you can use these components
to make secure trial version from
your application automatically:


but I'd rather recommand you to
separate demo and full version because
it's really easy for hackers to break thru.

LVL 13

Expert Comment

ID: 13423311
>>As a side line is it OK to have Delphi 6 and 2005 on the same machine?
yes, I have Delphi 5, 6, 7 and 2005 on the same machine with no problems

Author Comment

ID: 13423367
Thanks BlackTigerX, I'll give it a try.

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Expert Comment

ID: 13426671
You could try TurboPower OnGuard, a now open-source project, and therefore free to use.

LVL 22

Expert Comment

by:Mohammed Nasman
ID: 13426983
Ionworx have many tools that help you to do that, they are one of the best in this field for Delphi developers

Accepted Solution

DavidBirch2dotCom earned 500 total points
ID: 13430432
You might be interested in reading this excellent tutorial/ knowledge base for protecting Delphi programs


Expert Comment

ID: 13442081
Trying to protect your application is a waste of time, imho.

Be productive and add functionality :D


LVL 31

Expert Comment

by:Wayne Barron
ID: 13450614
We use AVLock Gold

Great product!

We have been using it for several years now.
And since we started using the new version.
It works great

Just use the source that added to the .dpr file.
And test it.

Since using the .dpr coding, it locks it.
Before, all of our programs was cracked.
Then we started using the new Pro & Gold
And no cracks was done.
For a year with over 4,000 downloads.
And a weekly search for Cracks on it, nothing.
None where found on the new version of our program
With using the AVLock Gold .dpr code.

Good Luck;

Author Comment

ID: 13453098
OK the fact that someone has developed a package which you can use, means that the know the encryption routines used in your app. So therefore I would rather stick with my own encrption method. My main problem is how to make the app time limited. I could monitor the date of file in windows that will not change, But which one? Which ever file I pick on, I will have to store somewhere the number of days to the expiration. Any other Ideas?
LVL 31

Expert Comment

by:Wayne Barron
ID: 13453500
Well, having the program read from a file that is "Time Stamped" on your computer.
All a Hacker will need to do is to monitor the installation of your program.
To find out what files are being installed and where these files are located at.

There are several programs readily available to download that do just that.
They monitor install programs.
Checking for:
Registry Enteries
File Placements

So anyway you look at it, if the program is good (or) great.
And is a major download on download sites, then someone somewhere is going to
Find out a way around it.

So your real only choice if you do not want to use an already redesigned component set
To help prevent easy hacking, is to release "2" versions of your program.

1st - Trial, Limited use of the program. But functional.
       Just do not add in ALL of the features into it.
       i.e.  A Text Editor, allows someone to use it with all features, excluding
       Open / Save capabilities

2nd - Full version that is sent via e-mail a download link for paid users.
        The download link will only be valid with a full completed :1: download
        Which is monitored on the Server-Side.

Our very first program that we made about 6yrs ago (I believe that is accurate)
The program was a MetaTag Generator.
Sold 15-copies of it in its first release.
Demo - Cannot Open/Save files.
But yet, it was good enough to bring in $25.00 a pop.
Each person we sent a download link to that was monitored.
Once the download was complete, the link became unavailable
So that no one else would have access to it.

But this did not stop a certain user from adding it to a File Sharing Progam
A year later. (That sucks)

So make your own decesion.
Either make a program that is basically worthless that now one will want to waste
their time attempting a hack.
Or release "Demos" And then on the Full Version, Have a Key for it.
you can always add something in it.

Take Care

Author Comment

ID: 13465228
Thanks for that David. I had seen this article previously but forgotten about it. I have managed to implement most of the good stuff and hope that my App does not get  hacked too much. I doubt I can stop it being hacked, but I need to have a mechanism where most users are forced to pay for the product after a certain period, If they really require it.

Expert Comment

ID: 13465448
Thanks for the points

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