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Trial versions of software from a computer date change will increase or not?

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artemlos wrote Jul 29, 2012 at 5:20 PM

Hi Mamirok,

It depends in what way the date on the computer is changed. If the user changes the time, so that it is before the creation date, the trial will actually increase. This can actually be avoided, by adding another if statement when validating: IF SetTime >= TimeLeft THEN the key is valid. This step will allow you to restrict the user from using the the application before the trial has started!

Although this will make it harder to roll back the time, people who really want to use your software more than you have specified will simply set their time to the key creation date of the key. Therefore, it is really good to use "feature locking" to limit the program from doing things, which should only be available for those who have paid for it.

Finally, I would recommend you, to make the software check the date on your server, because that cannot be changed so easily! :). Otherwise, you might want to try the example provided in the beginning of the comment!

Please let me know if I answered your question! :)

Regards,
Artem Los

artemlos wrote Jul 29, 2012 at 6:15 PM

Hi again,
Please take a look at http://skgl.codeplex.com/documentation#security, to see the code implementation for Visual Basic.NET

wrote Aug 14, 2012 at 6:43 PM

wrote Feb 14, 2013 at 7:45 PM

wrote Mar 22, 2013 at 4:11 PM

lberna wrote Mar 22, 2013 at 4:11 PM

I solved the problem this way:
see attached source.

Give me a feedback if this solution can be standardized.
thanks

wrote Mar 22, 2013 at 6:43 PM

lberna wrote Mar 22, 2013 at 6:43 PM

I solved the problem this way:
see attached source.

Give me a feedback if this solution can be standardized.
thanks

artemlos wrote Mar 23, 2013 at 9:30 PM

Hi lberna,

Thank you for the patch! I have included your solution to this issue. According to my unit test project, the code generates correct values, so I will most likely publish a new version of SKGL on the coming week.

Once again, I your improvement is great. Thank you!

/Artem

P.S. I will come with some more feedback soon!

wrote May 16, 2013 at 9:48 AM

wrote May 16, 2013 at 9:48 AM

wrote Jun 14, 2013 at 7:13 AM

artemlos wrote Dec 12, 2013 at 8:58 PM

The attached code can be found in https://skgl.codeplex.com/releases/view/107300