Hacking [Question] [3DS] It is possible to decrypt save backups made in system settings?

hanbaiki · Mar 14, 2021

The context is that I had an old 3ds and it broke the last year, I made some backups in nintendo system before that for some games and now that I purchased a new one I would like to restore them.

As far as I know, the backups from digital copies are encrypted, and if you don't transfer the data from that console or have an nand backup you couldn't do nothing..
I'm asking if someone know for a possibility to decrypt the saves with a external windows program or homebrew, the console doesn't work anymore and I never hacked it so I couldn't make a nand backup.
The SD card with the files and the 3DS folder works fine, so anyone know if with those files I could do something?

Thanks beforehand!

Kwyjor · Mar 14, 2021

While you can use ninfs to decrypt the files on a PC, you will still need the encryption key, movable.sed. This can be generated during the hacking process or extracted from a NAND backup (or essential.exefs).

If you don't have your movable.sed, then you can still generate it if you have another 3DS that has the Friend code of the broken 3DS in its Friends list. The Friend code alone is not enough – you need the actual 3DS that has the Friend code in its Friend list, and you need to run homebrew on it. (You don't need to do a full CFW installation – one of the userland exploits will do.)

Otherwise there is nothing that can be done. At this point, decrypting without the encryption key would take decades of computing time.

hanbaiki · Mar 14, 2021

I guess I can't do much on this case, Is impossible to add my old friend code..
I've been reading a thread of how calculate a encryptation key with an fake movable.sed
[sorry I can't provide full links with my current level in this site, the thread link is this:
''files-on-sd-card-not-loading-on-3ds.524684/'']

i'm not sure if I could do it, but at least I will give a try.
thanks for answering

lone_wolf323 · Mar 14, 2021

hanbaiki said:
I guess I can't do much on this case, Is impossible to add my old friend code..
I've been reading a thread of how calculate a encryptation key with an fake movable.sed
[sorry I can't provide full links with my current level in this site, the thread link is this:
''files-on-sd-card-not-loading-on-3ds.524684/'']

i'm not sure if I could do it, but at least I will give a try.
thanks for answering

unless you have your friend code, or someone else has it added. You cannot do anything with a faked one, It dont have the encyption key values you need.

hanbaiki · Mar 14, 2021

I see, thx for saving me time then..

Kwyjor · Mar 15, 2021

hanbaiki said:
I've been reading a thread of how calculate a encryptation key with an fake movable.sed
[sorry I can't provide full links with my current level in this site, the thread link is this:
''files-on-sd-card-not-loading-on-3ds.524684/'']

So, https://gbatemp.net/threads/files-on-sd-card-not-loading-on-3ds.524684/ .

The problem in that thread was recovering the movable.sed from a unit that had undergone a System Format. This is relatively easy as a System Format changes the movable.sed in a predictable way. (In fact, there's a gm9 script now that makes this recovery even easier.) But in your case you have no movable.sed to use as any kind of starting point.