Wii Help

Why can I not save games to a wii sd card and play them on a different wii console?

My friend has saved games on hes wii sd card and let me use it. But they will not save to my wii console, Why is this? Is there any way to transfer games from one wii to another?

Public Comments

1. As far as I know, that's an anti-piracy measure put in place by Nintendo. I don't think there is a way to copy downloaded games between consoles.
2. From what I can tell, Nintendo set up the Wii to store a small database of what files it has access to in the reserved section of the internal memory. In order to copy a save file onto the Wii, that Wii first has to have the game create a save file on it (basically installing the save file and writing to that database), then delete that save, and copy over the one from the SD card. Since Virtual Console game files can only be installed on the system through the Wii Shop Channel, this prevents widespread piracy.
3. Copied from http://wiibrew.org/wiki/Wii_Security Savegames on SD cards When you copy a savegame from your Wii system memory to an SD card (in "Data Management"), it encrypts it with an AES key known to all consoles (SD-key). This serves only to keep prying eyes from reading a savegame file. In crypto terminology, the SD-key is a "shared secret". Your Wii then signs the file on the SD card with its private (ECC) key. This is to prevent anyone from modifying the save file while it is on the SD card. If I then give you a copy of my savefile, your Wii can decrypt it because it knows the SD-key. However, it has no way of checking your Wii's signature, because it doesn't know my console's public key. To solve this problem, the savegame also contains a copy of my Wii's public key -- the one that matches the private key it used to sign the savefile. (This copy of my Wii's public key is called a 'certificate'.) Now your Wii can verify that my Wii signed the file, but it has no way of knowing whether it was really a real Wii that signed it, or if I just made up a new random ECC key to try to fool it. To solve this problem, the certificate stored inside of the savegame is then signed with Nintendo's private key. All Wiis have Nintendo's public key stored in their firmware; your Wii can use that key to verify the signature on the certificate. If the certificate is valid, it can verify the signature on the savegame against my Wii's signature. We solved the chicken-and-egg problem with our original memory-dumping hack. We extracted a private ECC key from one console. Since any Wii can read any savefile, we only need to have one key -- it doesn't need to be re-encrypted / re-signed every time.