There's no legal method to provide an illegal data.
As long as you allow users to obtain something for free that they should have bought is illegal.
Shifting, xoring, or whatever operation you do to the ticket key to provide it is still illegal. XORing it with another illegal key not provided to the user is probably grey area, depend on user's point of view. I'm not a lawyer and only see the end result or the shared data for what it is. "providing" is illegal. Keygen are illegal too, as long as you bypass the need to buy.
The simple idea to allow users to download a game without paying for it is wrong.
To me, it's even more illegal than sharing the common key. With the common key alone you can't obtain games for free, you can decrypt them but you don't allow installation and use.
If you use something which doesn't allow obtaining game for free (common key) to obtain it for free is illegal.
If I understand correctly what you want to do, it's only allowing users to decrypt the data downloaded from NUS but not providing the full ticket. (it could be re-generated to allow game install?)
but for that purpose, you will have to provide a list of encrypted keys to let the user decrypt it with the common key+GameID?
Where do you get these encrypted keys from? providing something that users can't get themselves is what is illegal.
edit:
A concrete example with games.
You own PokémonX and want a translated version.
- Providing original PokémonX ROM is illegal.
- providing a translated version of PokémonX ROM is illegal, so you provide only a patch of the difference.
- The patch data contains only the translated parts to apply to the ROM. If the user have the ROM he can apply the changes and obtain the SAME but translated game.
- If you provide a patch created from the difference between PokémonX and PokémonY, the patch itself is not a ROM and can't be played, alone it's not useful, but that patch is illegal (1 it contains data of the game and not amateur translation content, 2 it allows recreation of another illegal ROM)
- If the user happen to own PokemonX and apply the patch, he will now own a version of PokémonY that he didn't bought.
OK, I kinda see your point.
But, here's a couple of example for you to consider:
Let's look at a video capture card. It captures TV video input and saves a video file on a computer. These devices are perfectly legal (otherwise they wouldn't be at Fry's Electronics). However, these devices may also be used for illegal purposes, like recording a rented video. It's the USER'S CHOICE whether they will use the device for legal or illegal purposes, but if they do use it for illegal purposes, they may be prosecuted, but the manufacturer of the video capture card cannot be prosecuted for the users copyright infringement.
You buy a spool of yarn at a craft store. Nothing even the slightest bit illegal about that. Then, you use the yarn to strangle someone! You'd be guilty of first-degree murder, which, last time I checked, was illegal. HOWEVER, no legal action can be taken against the yarn manufacturer.
What I'm trying to say with these examples is that anything, no matter how legal it starts out, may be used for illegal activities. Here's that same example style applied to Uwizard:
Uwizard can download files from Nintendo's servers. Nothing illegal about that. However, the user may enter the common key to decrypt the files and steal copyrighted information. The user could also enter the title key for a game and download and decrypt that, but no legal action could be taken against Uwizard. I do see your point that it could be considered illegal for Uwizard to include a number that, when XORed with the common key, produced a title key. It IS sort of a gray area because the user must first obtain illegal information (the common key) to obtain a title key, so it COULD be argued that the illegal information came from the illegal common key and not the encrypted number. But, I won't do it this way unless someone can tell me for sure that it's legal.
I do have ONE MORE idea. The irrational number PI is NOT illegal, but, being irrational, contains ALL possible combinations of ALL numbers of ANY length. Meaning that at some offset PI contains EVERY ENCRYPTION KEY EVER USED! If I found an offset in PI where maybe the next 16 bytes were the common key, it would DEFINITELY NOT be illegal to share that offset. The only problem is finding it. I've already searched through 50 million digits with no hits for the common key. Just one funny thing to consider: PI actually contains ROMs of all games that Nintendo ever made and ever will make!
