Can I Create USB 3.0 Flash Drive With Undeletable Files?

Solution 1:

There is no way to make a regular flash drive read-only. At least not in such a way that it cannot be undone.

Some manufacturers works around this by creating a 3 in 1 device in which the seemingly single hardware contains an USB hub, the original device (could be flash storage, 3G etc) and an emulated CDROM drive. But that uses dedicated hardware, not off the shell consumer stuff.

For home users you could probably emulate this with a rPi or similar mini computer, though as far as I know those do not implement USB3 but USB2. The resulting device is likely either bulky or expensive.

Solution 2:

Yes you can but it highly depends on the controller. You need to find the right tool for the specified flash drive/controller(USB Mass Production TOOL, aka MPTool). With MPTool you can make a protected partition or simulating a CDROM, either way the file on it will be undeletable, at least from a normal OS or without MPTool.

Here is an example to get you some idea. Again you need proper MPTool for the controller and not all controller have the tool available.