I have customers who want to buy large amount of flash memories but he wants to copyright all files inside it.

The flash will contain files that will be delivered for his customers but they're not allowed to copy or delete any of the files the only allowed permission is to ready the files.

I searched and found many solutions but all have on function it WriteProtect the USB though I can't add files to Drive at all but I can delete or copy any file in the drive.

Is there any way to protect the flash memory so I can't copy data out of it?

  • Flip write protect to on and rip it off. – Cole Johnson Oct 6 '12 at 4:02
  • @ColeJohnson Not the case here: he wants to prevent copying files out of the flashdrive, not to prevent writing to the flash drive. – Renan Oct 6 '12 at 4:13
  • @Renan well, it will block deleting or writing to the drive ("but they're not allowed to copy of delete any of the files...) – Cole Johnson Oct 6 '12 at 17:09
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    The only real solution is to make your own flash drive that works in USB ports, but doesn't follow the USB standard. (use different port numbers internally). However, even that could be worked around if someone really wanted to. – Cole Johnson Oct 6 '12 at 17:10
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    Reading is copying. – kotekzot Oct 6 '12 at 17:45

Prevent people from copying files? You can't.

To put it shortly, if it can be read (or accessed in any other way), it can be copied, for a very simple reason: copying a file is loading it into memory and then writing it somewhere.

And even if this sort of protection was possible, it would be very flawed:

  • At the hardware level, you could connect a logic analyzer/data logger to the USB port and grab whatever is happening here.

  • If it's a document, you can write a program that just scrolls the window and takes screenshots automatically, then feed those to an OCR tool. Less than ideal, but it works to get the data out.

  • Even if screenshoting is not possible, you can use a device that records directly from the VGA/DVI/HDMI output of the video card and then use image processing techniques to retrieve the relevant content from there.

  • Audio/video files can be worked around by the above approach or even by pointing a camera to the screen or using an external recorder. (the so-called analog hole)

  • One can use another operating system which bypasses Windows-specific protections.

It is possible to think of other (sometimes convoluted) approaches to bypass those.

Copyright infringement is a people/legal problem and can't be solved by technical solutions alone - check how often DRM/copy protection systems (which is what you want) are broken.

  • Thanks for the info Renan well it's not a usual word or excel document something like that it's related to some program files all they care about is copyrights... So we are searching for a right solution ... for example in CD burning you can lock the CD so people can read the content of it but they can't copy it at all... – Cempron Koal Oct 6 '12 at 4:20
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    @CempronKoal How so? Once a file is 'read', it is in memory and can be copied anywhere with adequate tools. – Renan Oct 6 '12 at 4:21
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    @Cemron - ALL CD's can be copied. If you can "read" it, you can copy it. – Xavierjazz Oct 6 '12 at 5:25
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    @CempronKoal CD protection mechanisms have been bypassed easily, failed legitimate users and caused harmful side effects to user's data. They never had mainstream success. – Jesvin Jose Oct 6 '12 at 13:06
  • I wrote my own linux distro which mounts the drive and rips the C:/Users/* folder. It essentially bypasses the locks on the filesystem that Windows itself puts on it. Changing the statement from if it can be read to if it can be accessed. – Cole Johnson Oct 6 '12 at 17:04

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