CODEWITHSUNDEEP
c#drm
1Programmer
1Programmer

Reputation: 73

Set expiry date for application

I want to set expire date for my C# Windows application.

It means that i.e after 30 days my app won't work. It is easy to do when we use system time, it means whenever my program starts i check today date and expire date.

The problem is if the user changes system time, my comparison won't be correct.

What other ways can this be done?

Upvotes: 0

Views: 5327

Answers (5)

user1921
user1921

Reputation:

How likely is your app to be pirated and is it worth the time/expense to do anything more than cursory checks?

It might be easier to simply have two versions of a DLL - one that must communicate with a server every X days to make sure it's still active and the "unlocked" (purchased) version.

As has been noted, determined users will find a way around whatever you do so you have to evaluate effort/return to determine how much attempting to secure your app is worth.

Upvotes: 1

Zenwalker
Zenwalker

Reputation: 1919

May be keep a dummy .dll file in your app install folder, open it and keep the number of days and install date time. Every time application loads up, check it. .Dll files folks wont try to open and read. May be you can encrypt and store in it too. This could be very simple.

Upvotes: 2

Nick
Nick

Reputation: 3347

You could use a website that keeps the time to determine how long the program was installed.

You are probably going to get advice saying that it is not woth your effort.

Upvotes: 0

Bas
Bas

Reputation: 27115

The first line of defense is to check with a server, checking out their system time so that the user cannot change his own. Also try to hide the start date (under some dummy name in the registry perhaps). These are pretty futile things though, smart users will be able to 'crack' this with minimal effort.

Upvotes: 1

Jared Peless
Jared Peless

Reputation: 1120

I would figure out a better way to get people to want to pay for the application, because fighting it can be a very futile effort, although you can make it more difficult with things like hardware dongles, phone home services, etc. If your price point is not high, customers won't want to put up with this.

Upvotes: 4

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