Encrypting a thumb drive - a simple solution please.

I want to encrypt the jpg images and text on a thumb drive to avoid the data falling into wrong hands, a very simple program which I imagine would take each byte in a new version of the file which had been edited, change it via an encryption password to something else following a routine, and save that new file on top of the old. I would then later load that file into a companion de-crypting routine to recover the original to use and re-save via encryption. I have a 3.5 GB thumb drive that would be big enough and conveniently portable. My requirements are very simple - no bells or whistles needed.

I have tried several free programs but they either don't work for me or are over-sophisticated and complex. I don't want to encrypt my whole internal documents drive nor a partition in it.

Can anyone suggest a simple solution please?

Thanks.

With BitLocker is possible to encrypt the whole thumb drive [UFD]. I used this method in the past, until I ran into problems [unable to decrypt the UFD].

Now I don´t encrypt the UFD directly, but use a VHDX virtual disk encrypted with BitLocker. This method can be used to encrypt the whole UFD or part of it. It has worked well for me, although Windows usually produces "error" messages, false positives, when I insert the UFD, before I enter the password. To create a VHDX, it´s necessary to use Win 10 Pro, but it can then be used in Win 10 Home or other versions.

Another option is to use VeraCrypt to encrypt the UFD. This can be done in any Win 10 version.

Depending how much data simply creating an encrypted rar file