Distributing Applications on 30 days trial basis?

[piscis]

Gentleman:

Can you guys give me an idea on the Software or Code needed for distributing Windows Desktop Applications on 30 days trial basis and providing the user the option for turning the trial into a full version?

Thanks

Andy

[MrGTI]

I too have wondered about how to do this. If you write anything into the registry or an INI/XML file, the user can easily find this using various scanning tools.

The best solution i came up with is to create a sample version that has the expiry date hard coded right into the EXE. The only way for them to continue using it would be to change the clock on the computer.

But even then you can do a check to see if the date is less than a certain date, and make the program crash if it is.

That's the best i've come up with.

[Pirate]

Date-based tech is old and easy to break . Better than that is to count execution number and save that in the reg or hidden file with sort of encryption . No one can get it unless he has the encryption key . I've never done such ways but seems to work well though .

[sunburnt]

That seems like it would be fairly easy to break too. Just store the encrypted value from the first execution and continually revert back to it after every run.

[hellswraith]

There is no guaranteed way to make it un-crackable. If there was, don't you think MS would have done it by now?

Now, what you have to do is make it hard enough that the average user couldn't figure it out, and flexible enough so that you can recompile every so often making keygens and cracks for your application a non issue. There is always going to be a few copies of your application that is cracked and used by people. This is called shortage in the retail industry, but unlike the retail industry, it doesn't cost you a thing if it happens. You just need to keep it in control as much as possible. If it gets too crazy, then you start to lose sales, and that is when you have a problem.

My rule: spend less time on the security, and more time on the quality and features. That extra time spent will help sales more than if you added the worlds best security.

[RichardAtherton]

I agreee with the sentiments of concntrating on quality rather than security, however I am faced with the same problem.

The current solution I have is date and count based, with an encyptation key (it's in the help of VS for encyptation).

Thta's simply to stop the application being easily copied but any determined person can still break it - but that's life and that's what copyright laws are for so if you do see it being copied illegally you can act.

Alternatively search the NET I have seen at least a couple of software packages that provide registration services software.

[MrGTI]

Isn't there something in .NET called 'Code Obtusion' to prevent hackers from decompiling and altering it?

I agree with more work on a quality product. If you make a stable product, and sell it at a reasonable rate, people are less likely to rip it off.

[Pirate]

I can think of many trick and new ways but I won't say them . Sorry .

For MS programs and piracy , I would say , Piracy what made MS well-known company . I know they can invent the most secure tech but it seems they don't want to .

[piscis]

Pirate / MrGTI / RichardAtherton / hellswraith / sunburnt

Gentlemen:

I like the idea of the 100 hours of use.

Would it be possible to have a timer inside the same application that will start running only when the application is started and will maintain its value even when the application is not running any longer?

This way we do not have to depend on the Registry. Can this be done, If so how?

Andy

[PT Exorcist]

Originally posted by MrGTI
Isn't there something in .NET called 'Code Obtusion' to prevent hackers from decompiling and altering it?

I agree with more work on a quality product. If you make a stable product, and sell it at a reasonable rate, people are less likely to rip it off.

code obfuscation?

[Pirate]

Originally posted by PT Exorcist
code obfuscation?

Apparently MrGTI meant that . This obfus. thingy just convert the IL code to native code .

[Pirate]

Originally posted by piscis
I like the idea of the 100 hours of use.

Would it be possible to have a timer inside the same application that will start running only when the application is started and will maintain its value even when the application is not running any longer?

This way we do not have to depend on the Registry. Can this be done, If so how?

You can try to make external application that checks for whatever you want and be Windows Service at the same time .

[MrGTI]

I was close. From Microsoft's website:

Source code obfuscation
Integrated source code obfuscation secures your intellectual property, further reduces the size of your .NET-connected applications, and improves the performance of your applications. Code obfuscation is available in Visual Studio .NET 2003 Professional, Visual Studio .NET 2003 Enterprise, and Visual Studio .NET 2003 Enterprise Architect editions

The problem with making it only work for 100 hours is that you still need to store the number of hours used somewhere.

[Kasracer]

You have to be creative. When the program is run, it will check if a file exists, if it isn't there it creates it. Name it like vbrun.dll.ini or something so if they have the hide extensions, they won't know any better. Would you delete vbrun.dll? didn't think so.

Then make a registry entry in a system area but hidden very deep. Have both keep a number of how long it has been used for. If the person finds 1 of them and edits it, the program checks both as it starts up. It will take the higher number if both are different, then save over the lower number when it's done added the time it used.

Get even more creative and make more files.

Even better, create a folder and name it sys.dll or something. People will think it's a system file especially if you put the icon on it, but it's still a folder.