License keys system
Posted 28 July 2009 - 07:29 PM
I want to A: prevent the game owners from making copies that can be played on a different computer unless they disable the use of their copy on the original computer(only one computer at a time can be used with each game copy)
and B: stall the inevitable cracking by piraters for a long enough time to get some decent sells in first.
How would I go about making a license key system that accomplishes these two things?
(and this is by selling downloaded copies through an online store)
Posted 28 July 2009 - 10:57 PM
I also need help on how I'm going to get IP's before buyers download the game, and then I need help finding a server that checks the IP when the game is played.
Posted 28 July 2009 - 11:07 PM
Anyway, one way you could implement machine IDs (and bear in mind I have no actual experience implementing license systems, so I may be overlooking something obvious) would be to create an RSA public/private key pair; keep the private key to yourself, and have the public key hard-coded in the game. Then, when someone registers, send their MAC address to your secure server, encrypt it with the private key, and send back the ciphertext. When the game starts, decrypt it with the public key and check that the MAC address matches the machine on which it's currently running.
You still need a server to handle registrations and allow re-issuing the license if someone wants to move to a different machine (or if they replace their network card), but people won't need to connect every time they play the game, which is much more convenient for them and reduces the load on the server for you.
Posted 28 July 2009 - 11:44 PM
I wouldn't really worry too much about user registering the game on multiple PC's without unregistering it first. It would strike as an inconveniency to legit users and isn't really your major concern anyway. You want to prevent your game being distributed in torrent sites, etc. thus it's better to think a mechanism to protect your game from that.
Posted 29 July 2009 - 01:19 AM
The next step was I put in a simple serial number system with a basic key-seed. Anyone that really wants to pirate it still can without much fuss, but the typical game player would not know how. I am guessing, the simple protection system probably reduced my piracy significantly.
Now, here is the twist. To an extent, I am not too bothered by torrent copies or pirated copies... those people would probably never have purchased anyways. This can be used to an advantage in a sort of viral way.
If someone downloads a torrent copy, good chance its going to be a old version. I do regular game updates and plaster the version number right on the game gui. If someone likes the game, but they have a old pirated version, there is a good chance they will not find the latest build, so hopefully they turn into paying customers, customers that would probably never have heard of my game if it were not for the torrents.
Posted 29 July 2009 - 02:32 AM
here is how u go about doing it. http://www.wd-3.com/...e/luserland.htm
u may not want to go as far as this article leads u to.
good luck with your game.
Posted 29 July 2009 - 02:55 AM
Does anyone know of something I could use that helps set up a license key system with minimal work on my part?
Posted 29 July 2009 - 03:41 AM
This is a model you can build off of, so it's future-proof. Your first version may just be a basic serial validation scheme, but over time you can refine your business models and introduce new DRM features.
Posted 29 July 2009 - 04:34 AM
You could also use the status returned from the various anti-debugging code to flip randon bits of data, or even code, instead of flashing some error. This way, it will take the game much longer to expose all of its safeguards, and although it won't stop the crackers, it should pose some challenges for them :)
Posted 29 July 2009 - 09:19 AM
When a trap is triggered, you just terminate the game with an appropriate message. I think it's bad idea to make your game crash randomly because that's very bad publicily for you and people will think your game is badly coded. Doesn't matter if the publicity is unjustly distributed by pirates, since people wont know that and if the crashes occur due to the protection or badly coded game.
So, legit users go online to register the game for given CPU and the registration process changes bytes in the exe to make it run on that CPU. Unlike Steam, you never need to go online after registration for that CPU, so it's actually convenient for users.
Posted 29 July 2009 - 10:56 AM
This is what i did:
- each time "game" (in my case its an application) starts, it needs to authenticate to my server (serialkey)
- the server tracks "logins" and "logouts" (game closes) and also take care of timeouts and possible client crashs
Now comes the main part, after the login the client gets a small dll (which will be never stored to hd). This dll has some important and essential code which is needed for the client in order to be able to run properly. This way i am also able to provide some updates (thoses code in the dll need to be choosen very wisely!). So removing protections and other usual things won't help since you still need the dll and only with a valid serial key the server will send the dll. Of course a hacker could intercept the returned dll (which is also encrypted) and make a workaround, but this is much more complex.
With enough talent, motivation and time a hacker could always break a security system.
Posted 29 July 2009 - 12:46 PM
To be perfectly honest, I don't know a thing about software copy protection, other than it's recurrent theme of inevitable pirating success.
I'll use any effective enough method, but I need something that doesn't require any knowledge of what you're doing, just using a "wizard" -like program to help you set something basic up automatically for you.
Posted 29 July 2009 - 01:05 PM
And the online-check is short and only at the beginning.
Posted 29 July 2009 - 01:19 PM
2) people who bring their laptops along with them (to airplanes, coffee shops, etc.)
3) people whose ISP sometimes is screwed (mine was just couple of days back)
4) your server may be off-line
Requiring online connection to play your game is a bad idea.
Posted 29 July 2009 - 01:21 PM
Crackers have cracked most mechanisms out there for any game with strong stand-alone presence, within days in the worst-case scenario. The more popular the game, the faster it will be fully cracked. Downloadable content doesn't stop them. Sims 3 content packs were available on the net within hours! For AA and AAA titles, they actually sometimes have people and/or systems "on the inside" getting them early copies to get a head start. I've seen big titles released in cracked form before they even hit retail! In fact, the race is on to get your cracked version out first, with trojans, so as to get the most systems.
The only copying you can deter is casual copying, and for that you don't need much. I'd look for canned systems (ex: Silicon Realms' products) and not waste my time and resources on developing my own "new and improved" scheme that will just as likely fail. Also, don't get seduced by promises of far-reaching DRM. You pay a lot for not much gain.
Yet, you should still have accommodations that allows a handful of installs for homes with multiple systems, or people that frequently change systems, or that are not online all the time. AticAtac's mechanism is an example of bad idea for people who aren't online all the time. Nothing I hate more than being stuck somewhere with bad connections and not being able to take a break with game X because of some online requirement. Not only do I end up hating the game, I likely won't buy again from that vendor...
Also, if you develop your own canned solution, don't forget to keep in mind the ignorant end-users. Lots of people may end up with a cracked game without knowing it. If you make a game behave erratically or do something damaging, they will blame you, not the cracker. Worse yet, a class action suit...
Most people who torrent casually frequently infect their systems and render them inoperable, so they eventually get what they deserve and hopefully learn from it.
Those who are veterans are armed with some intelligence and are pretty much unstoppable, because they are plugged into how and from who to download their warez.
Posted 29 July 2009 - 01:23 PM
And the online-check is short and only at the beginning.
Apart from Jarkkol's bang-on comments, the one thing any shop (esp. resource-strapped indies) should fear is lighting up my support desk by using some sort of DRM that people don't see, don't understand and limits them at points that exacerbates the frustration factor.
Posted 29 July 2009 - 04:14 PM
I would think a one time online registration is not a big deal. Have a backup way that you can manually get them registered by phone for that 1% that are not able to active online.
Posted 29 July 2009 - 06:37 PM
Posted 30 July 2009 - 06:41 AM
I wrote that i used it in my case for an application !
And for this case it worked perfect and still is.
There is no general out-of-the-box copy protection, it all depends on the application/game and the user, etc.
You define who you want to reach, "people behind secure firewalls", at coffe shops, etc. cann't run the application , that may be < 5% of users and i can live with that (thats for my case, everyone has to decide for himself).
I still think the future belongs to games which run most of the game codes on server (like MMO's), its a perfect copy-protection.
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