[POC] Game Cartridge Steganography

Discussion in '3DS - Homebrew Development and Emulators' started by SubstituteCS, Oct 22, 2015.

  1. SubstituteCS
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    SubstituteCS Advanced Member

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    Introduction

    What is "Steganography?"

    Steganography is, "the practice of concealing messages or information within other non-secret text or data."

    Well, it's pretty common knowledge that the data on your game cartidge is non-secret data, however your game save is a bit of a gray zone.

    Now wait, if anyone can do this, what makes it so secret?

    What makes it secret is that any interceptor will be unaware of what information that they have until it's too late.

    Let's take Mario Kart 7 for example.
    On boot, if the game detects in invalid save file, it automatically deletes it and replaces it with the default save. This effectively hides your data from someone who's unaware that it's on the cartridge.
    Additionally, MK 7 has a replays folder, which as you can guess, contains replay files, or at least what looks like replay files.


    How it's done

    *** FIRST AND FOREMOST, BACKUP YOUR SAVE DATA ***
    *** THERE IS A FILE SIZE LIMIT.....IT IS DIFFERENT FOR EACH GAME ***

    Hiding Files

    1. Download svdt and put it on your SD card
    Link

    2. Place all files you want to put onto your cartridge onto your SD card

    3. Boot into the Homebrew Launcher and start svdt.

    4. Delete some files from your game cartridge. (Games with replays work well for this!)

    5. Hop over to the SD card portion of svdt and copy the files you wish to save into the game cartridge. (Make sure you put them in the correct folders!)

    6. Exit svdt

    You have now hidden files within a game's cartridge, congratulations! Assuming you didn't delete your game save, you might just get away with having a working game at the same time!


    Retrieving Files

    1. Launch svdt again

    2. Navigate to where the files were placed (e.g., replays folder)

    3. Copy each file to SD card

    OR


    2. Copy the whole folder to the SD card

    4. Delete the files from the game cartridge

    5. Restore any data you need to from a backup (e.g. a game save.)

    You have now retrieved those hidden files, congratulations!


    Usefulness

    You could use this to mess with friends, or in some more oppressive parts of the world, you could hide incriminating files.


    I have personally tested this with Mario Kart 7 with placing files into the replays folder. The game remains none the wiser (I didn't check if it "sees" the "replay" file in the replays menu of the game, but I know it won't load it.)
     
    Last edited by SubstituteCS, Oct 22, 2015
  2. Marko76

    Marko76 GBAtemp Psycho!

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    Really don't mean to take a huge shit all over your thread but this really is the most useless use of homebrew I have seen in a long time. Why would I take my sensitive data off my pc or phone and hide them on a gamecart when I could just use any number of programmes available on my PC and phone and hide them directly with way better protection IE secure passwords than this does.
     
  3. SubstituteCS
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    SubstituteCS Advanced Member

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    For starters, it less obvious that you're transmitting sensitive information if you're giving a friend of yours a 3ds game, versus a highly encrypted flash drive or other device.
    I'm not sure how good your reading comprehension skills are, but this was about "steganography" aka "the practice of concealing messages or information within other non-secret text or data"
     
    Last edited by SubstituteCS, Oct 22, 2015
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  4. DjoeN

    DjoeN Captain Haddock!

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    Somewhere in this potatoland!
    Ok, now the FBI/CIA/NCIS/Homeland Security/and whatever, have to confiscate all 3DS games taken into the office to check for confidential files!
    @SubstituteCS has now made every 3DS user into a potential spy/leak or whatever :P !
     
  5. Marko76

    Marko76 GBAtemp Psycho!

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    So the people who would have a interest in my secret data would be my friends who all use homebrew on 3ds most of them use this site as well so they now would know to check all my 3ds carts for hidden data like I said I would rather hide on my PC with password as it's way more secure than this. And as for your insult in regards my reading skills was that really necessary?? For 1 i am severely dyslexic and no I'm not just saying that because of what you said I have discussed my dyslexia in other threads and for 2 I fully understood what you had wrote in the first place all I did was point out how it's easier and more secure to hide things on pc than this method.
     
  6. SubstituteCS
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    SubstituteCS Advanced Member

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    You have still missed the entire point of steganography.
    Steganography isn't about hiding a file on your PC with a passphrase, it's about hiding a file in the open. It's the ultimate version of "act cool and we don't get caught."
    And yes, steganography has many uses, take Jeremiah Denton for example who used steganography in his POW "interview." His voice said everything was fine, but his eyes (or rather eyelids) said torture.
     
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  7. Vague Rant

    Vague Rant Deceptively cute

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    @Marko76, This is not about hiding things from your friends. I believe you are missing the point entirely. Picture James Bond trying to get some Russian state secrets to another spy without just firing up AIM or something. Bond doesn't just want to stash them on his computer, because computers are pretty good at getting compromised by spies. This is a way for James Bond to do spy things in an unexpected way.
     
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  8. Marko76

    Marko76 GBAtemp Psycho!

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    @Vague Rant I do get it the point I think I am trying to make is the kinda the same as DjoeN hinted at and that is the op has posted how this works and by doing that he has pretty much rendered it useless because not only would James Bond now know how to use this on 3ds but also the bad guys have been told all about it. So yes purely as a POC I get it but in daily use its pointless for the very reason I have said before IE now everyone knows to check 3ds carts for hidden files.
     
  9. SubstituteCS
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    SubstituteCS Advanced Member

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    Hop off, as it's clearly not entirely useless.
     
  10. cearp

    cearp the ticket master

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    i was thinking about stuff like this recently, interesting ideas.
    send games to people and only if they have a hacked 3ds can they view the files.
    or maybe use a hardware tool to dump the save, but you would still need a hacked 3ds to decrypt the dumped data
     
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  11. keanutah

    keanutah GBAtemp Regular

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    This is actually pretty cool.
     
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  12. LuigiBro

    LuigiBro GBAtemp Regular

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    Will this work with SUPER MARIO 3D LAND?
     
  13. romanaOne

    romanaOne GBAtemp Regular

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    where the potential goes to zero
    There are plenty of places a message can hide: I remember something about XORing simple text data with a lossy compressed file like jpg or mpeg and there is no obvious damage to the file. This is going back a while, but it was really easy to do even in a total crap high-level language like Mathematica.

    Most people don't think to shave the messenger's head but instead are distracted by the locked box he's carrying.
     
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  14. SubstituteCS
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    SubstituteCS Advanced Member

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    It should, but each game has a different amount of available memory.
     
  15. jamieyello

    jamieyello Professional Dumbass

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    That's actually brilliant if I'm understanding this... you can put encrypted data on a hard drive and after enough hacking at it people are going to get it. No one is going to look inside Mario Kart 7. That's really clever.
     
    Last edited by jamieyello, Oct 22, 2015 - Reason: i wanna say bad grammar
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  16. Jwiz33

    Jwiz33

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    in the illuminati headquar—I have said too much!
    This is great! I don't have anything secretive to hide though. Maybe I could make a text diary? lol
     
  17. shutterbug2000

    shutterbug2000 Cubic NINJHAX!

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    Nice! Now we just need to find what games have the biggest storage sizes
     
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  18. Pedeadstrian

    Pedeadstrian GBAtemp's Official frill-necked lizard.

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    Until they read this thread.

    But how does this allow one to "mess with friends?" What's the scenario? You give them a 3DS game and they play it without knowing something is hidden in the files? No loss on their part.
     
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  19. zoogie

    zoogie simple pimp tool

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    Just find a random encrypted 3ds rom on your hard drive and embed your encrypted files somewhere in the middle. It blends in perfectly and no detective is going to go through your 3ds roms looking for random AES encrypted files.
     
  20. Jwiz33

    Jwiz33

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    in the illuminati headquar—I have said too much!
    A good way to store your nand backups, if there is a game that has that much space.