... this particular SD card probably has seen a rPi, the Switch formatted it before use, and it hasn't been in a rPi after that.
I also still haven't used this SD card with a pi since formatting it with my Switch, and I haven't modified any files from my computer, so all the files on the card are ones the Switch has placed there. Plus I don't think the rPi would store its crash dumps in /Nintendo/saves.
I formatted a different card (same model and size, though) and put it in. The files the Switch created on the "fresh" card did not contain any of the strings in the other files.
Hi DerpyEagle,
It's a fluke event. Here's an explanation that is as simple as I can make it.
1. The SD card was previously used in a RPi. The RPi stored data on the SD card.
For sake of explanation, let's say the layout was as follows:
Sectors 0-99 == File system (list of directories and where to find files), with pionters to sectors 100-199 for file FOO.TXT
Sectors 100-199 == the data of file FOO.TXT
2. The SD card was then "formatted", which only clears the file system.
For sake of explanation:
Sectors 0-99 == File system, with sectors 100-199 showing as "free" ... available for use by the next file to be created... no "FOO.TXT" file exists anymore
Sectors 100-199 == Still contains the data of the old file FOO.TXT (format does not overwrite data... it'd take really long time...)
3. The SD card was then used by the Switch, and it created the files you noted. When allocating space for that file, it included sectors 100-199, as they were showing as "Free space" in the file system.
For sake of explanation:
Sectors 0-99 == File system, now with sectors 100-199 showing as "used" as part of the file 8000000000000000 etc.
Sectors 100-199 == Still contains the data of the old file FOO.TXT
4. the Switch writes to sectors 100-149 when writing to file 8000000000000000.
For sake of explanation:
Sectors 0-99 == File system, now with sectors 100-199 showing as "used" as part of the file 8000000000000000 etc.
Sectors 100-149 == now contain new, switch-specific encrypted data
Sectors 150-199 == Still contains (part of) the data of the old file FOO.TXT
5. User runs strings on the files that appear on the SD card, and finds unencrypted data with interesting strings.
This also explains why, when you put a different (clean) SD card into the system, no unencrypted strings appeared in those two files. Sorry, but it appears that you just found old data because the switch didn't use all the space in the file... it just allocated it ahead of time.