Heyho. I spent the night with trying to decrypt the Mario Kart 8 network traffic and had some success! After a bit of guessing, I was able to find the RC4 Encryption/Decrytion function that Mario Kart 8 is using to encrypt/decrypt some of it's data. The source code of my current PoC and more information can be found here: https://github.com/Maschell/nn_nex_logging_and_research Little story how I found this: https://pastebin.com/n8FcnJtt It looks like games are sharing the nn::nex library for their online gaming stuff. Does anyone know other games that has a .rpx with symbols in it (and online functionality)? It looks like Mario Kart 8 's nn::nex is not matching 100% the Sonic Allstar Racing nn::nex, so probably there different version out there. Did anyone tried something similar yet?