I built a Linux CLI tool that encrypts and decrypts folders using AES-256-GCM. It also hides file and folder names and stores the mapping in an encrypted file.
> When loading a key, it looks for meta.sec on the detected USB drive.
I would not trust a thumbdrive with a key that wasn't backed up elsewhere. Those things are unreliable on a good day, and I don't like data loss.
If this is a learning exercise, cool!
If this is a real thing, it needs a lot of work. Lots of failure modes, errors that are not being handled, sometimes exceptions, sometimes swallowing and printing to stdout, very inconsistent style, mixing and matching all kinds of C and C++ conventions, the fallback hard coded path of your specific user name + deep path ...
I would recommend not using this for any data that you actually care about.