I needed a possibility to create an encrypted space on USB sticks so that the data is not readable if you loose such a stick somewhere. Although there is BitLocker To Go and VeraCrypt, I ended up with a tool called SecurStick as
- it is available for Windows, Mac and Linux
- it does not need an administrative account
- supports also unencrypted files on the same stick
Daniel commented below that Cryptomator also has a portable version which does not need administrative rights. I tested it and it looks good. As Cryptomator is still a supported tool (SecurStick is old code which is no longer maintained) I will us ethat for my USB sticks at least if the data exchange is between Windows computers only. I think that for the Mac and Linux version it is not so easy to use it without installation. Currently I have no machine to test so that I could not try it by myself.