I would like to remove all traces of homebrew on my 3DS. Yes, this is a precaution against getting banned. Before the inevitable "There's no point now, Nintendo has logs going back months!" argument, hear me out on my situation. I lent my 3DS to a friend in early 2016. I told him not to install any homebrew, but when I got my 3DS back a few weeks ago, I found out that he had anyway. I was a little annoyed by this, but decided I would find out how to remove it at some point. Well, now is that time. The 3DS hasn't been connected to the Internet for at least 3 weeks, so there is a chance that if I remove everything it will never get flagged. I have no knowledge of the 3DS scene (except what I have picked up in the past few hours), but I have some knowledge from the Wii scene. I also have a master's degree in computer engineering, so if you can give me instructions in generic terms I can work with you. What I want is for all non-volatile memory on my 3DS to be in a state that would look like a clean Nintendo-compiled or Nintendo-delivered version that would be valid for my New 3DS XL. I am aware that these types of binary images are now encrypted machine-specific. I'm assuming that this is why a file called "OTP.bin" is featured in some homebrew guides. For those of you who haven't studied cryptography, OTP stands for "One Time Pad", which is a collection of random bytes (or a seed for a PSRNG to generate a collection of random bytes) used by a stream cipher (or sometimes just XOR) to create a binary with uncrackable encryption unless the OTP can be recovered. This would be analogous to keys.bin in the Wii scene, which was used to encrypt the NAND. Speaking of the Wii scene, just a few years ago a tool was released that enabled the creation of machine-specific NAND images "from scratch": as long as you had keys.bin and the unencrypted binary components of the NAND image, you could use this tool to compile a fresh NAND image that booted on your Wii. Is there any similar tool or method for the 3DS? If not, what should I do to completely erase all traces of homebrew from my 3DS? If it helps, it looks like I have A9LH, Luma, and System Version 11.2.0-35U My friend is not very careful, so I doubt he has a backup of my OTP or my clean NAND, although I will ask him. Back in university I was a Linux sysadmin for the department, so remote backups of anything important would have been my first priority if I had done this myself. I also would have turned off SpotPass immediately (which he did not). Can you tell that I'm a little bit pissed off about this whole situation? I bought a pristine New 3DS XL and never wanted to installed homebrew on it. The reason I mention that is I see some guides on how to recover the OTP, so if there is such a tool I could follow one of those guides and recover my OTP. Here are some additional questions: Is there only one physical non-volatile memory on the 3DS? Do boot-time exploits of the arm9 and arm11 modify firmware that resides on those chips themselves?