How to protect my license from Date change?

Question

5.00/5 (3 votes)

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I made a c# program with an expiration date (100 days after the program is installed)
the code is:

DateTime today = DateTime.Today;
DateTime Expiration = today.AddDays(100)

;

but if the user who bought my program changed his computer's date to a previous time ... the license will be valid forever
Do you have any suggestions to solve this problem???
thanks,

Posted 19-Sep-11 7:28am

George_Rasmi

Updated 19-Sep-11 10:45am

RaviRanjanKr

v2

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#realJSOP · Accepted Answer · 2011-09-19T07:35:00

Solution 1

Save the date every time the program is run. Then you can check the date it was last run against today's date. If today's date is equal to/earlier than the last date run, don't let the software run.

How you implement something like that is up to you.

Posted 19-Sep-11 7:35am

#realJSOP

Updated 19-Sep-11 8:30am

v2

Comments

George_Rasmi 19-Sep-11 19:20pm

nice idea :)
thanks John

Philippe Mori · Accepted Answer · 2011-09-19T13:28:00

Solution 2

You can also check the time on the web.

Posted 19-Sep-11 13:28pm

Philippe Mori