I would like to create a password protected file or folder which can be
opened only once. It does not matter what software I need to use since I will
have to obtain it anyway. It can also be one use only disposable memory stick;
I really don’t know how to approach this problem and any suggestions would be
In this excerpt from
Answercast #64, I look at the possibilities of locking down a file to be
read only once.
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Unfortunately, I have exactly zero suggestions for you.
I’m not aware of any technology that would allow you to do what it is you’ve
I also want to caution you. My biggest concern here is that what you’ve
described could give you a false sense of security.
Files can be copied
For example, what if the one time a file was unlocked (from
whatever technology you ended up finding), it was used to make a copy of the file?
Well, that copy is no longer locked – and is available forever. The
file that you gave them would presumably self destruct (or continue to be
locked or whatever), but there are just so many ways that data that is visible,
that can be unlocked even once, can be copied – that I’m really, really
concerned that while you might think you’re solving a problem, that problem
isn’t really solved.
So I would encourage you to go back and really try and understand exactly
what it is you’re trying to accomplish here. I’m not aware of any technology
that will do what it is you’re asking for; and in all honesty, I wouldn’t trust
any technology that did.
Answercast #64 Back to – Audio Segment
3 comments on “Is there technology that would allow a file to be opened only once?”
Too much mission impossible?
This is possible (with one gotcha, see para below) and does exist. Basic concept is that software on a computer provides the DRM shell. It opens the file AFTER verifying the ID of the user AND phoning home to a remote server to check on the rules for that user and that file. Rules can be: open only x times, open only on this computer, open only until next Thursday and/or do not open unless the rules can be verified. Thus, there could be no off-line access allowed. One such product is at http://www.locklizard.com. There are others.
Of course, once a file has been opened and viewed, nothing stops the end user from taking a picture of the computer screen with a camera. So, take all of this with a grain of salt.
I definitely agree with the second part of that statement, 100%. For anyone who might ask “why”, just use your favorite search engine and look for “Sony rootkit”, a horrendous problem caused by Sony attempting to copy-protect their CDs.