Paul Johnson wrote:
How do you secure privacy of files on a USB stick?
encrypt the filesystem,
The usb flash memory stick works fine if it is VFAT, but what if you are worried you might lose it and then anybody could read your secrets. Or, if you need to share a file to somebody, but don't want them to read everything else, what do you do? I thought I could fix that by putting on an ext3 file system. But it doesn't help. Windows users with IExplore can see all the files, no matter who owns them.
really? Did you add ext3 support to Windows? if not, then my next guess is that you're confused!
On a Linux system, the owners of the files are not recognized. I had forgotten that ext3 uses user numbers, rather than user names, for ownership information. So when I take a disk from one system to the next, then the user is either unrecognized or wrong. Here's a case where it is unrecognized: drwxr-xr-x 3 29999 29999 4096 2007-11-26 19:50 Booger
It's not wrong, it's right in the current context. The mapping between names and numbers is merely for human convenience. Archive utils such as tar try to preserve both, but restoring in the wrong context can be problematic. Just as you're seeing here.
I've seen other cases where another user who happens to have the same user number is given ownership of my files. So, apparently I can't rely on the file system permissions to give me any security. Aside from tarring up stuff that I don't want to be public and encrypting with a gpg signature, I'm stumped on what I should do. Can you put an encrypted file system on a usb flash disk? How?
I've not tried creating a new filesystem on a flash drive, but I know my boss reformatted one on his Mac, with the result I couldn't read it on Windows.
If one only wants to use part of the USB disk, it's possible to put a big file on it:
dd if=/dev/zero of=/media/USBDISK/bigfile bs=1M count=512 and create a filesystem: mke2fs /media/USBDISK/bigfile I can't advise on making an encrypted filesystem, I've never done it. -- Cheers John -- spambait 1aaaaaaa@xxxxxxxxxxxxxxxx Z1aaaaaaa@xxxxxxxxxxxxxxxx -- Advice http://webfoot.com/advice/email.top.php http://www.catb.org/~esr/faqs/smart-questions.html http://support.microsoft.com/kb/555375 You cannot reply off-list:-)
