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make a file self destruct
- Thread starter rock6079
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Depends. If you're talking about a self-destructive file on the CD itself, then no, I don't think that's possible. If the person copies that file to the computer, however, that's different. I suppose you could attach some sort of script or macro to it to destroy the document by writing random stuff to it after a certain date or time. Or a script to erase the file completely from the computer. But then it also depends on how sensitive a file this is.
With a plain word file copied to any old PC, the only option I can think of is to use a macro to do something to the file or it's content when it's loaded into Word. These are easily bypassed though, so it would by no means be foolproof. You could pretty easily view the file that's on the CD and get the content anyway, so I think you might be up a gum tree with this one.
You could put a thin layer of C4 or something like that on the CD starting just at the end of the file, that way after the CD drive has read the file once, the disc goes boom.
What is your purpose? Is it to make sure that nobody but you can use the file on the CD? Is it to make the CD usable once by someone and then never again by anybody? Is it to make sure that anybody can use it once on a given computer but never again on that computer? Is it to make sure that the file works for anybody up to a certain date/time and then never works again for anybody?
Doctor Q said:
the purpose is as simple as i am giving a word document to someone on a cd, they will copy the file from the cd to the computer and then give the cd back to me, after a day or so, id like the file to n olonger be readable, or get deleted from the computer it was copied to. wouldnt have to b foolproof or ne thing bc the person woulndt expect it and wont be resavingt it or copying the text
Except it would burn and not explode. Actually, that would be just as effective, and much safer. Less shrapnelstoid said:
If you let them launch the real MS Word application, I doubt you can prevent them from saving a copy of the document. So I imagine you'd have more luck if you created an application to display the same text. I don't know how to write the application I'm talking about, so I am only speaking theoretically!
Assuming that they give you the CD back before they try opening the file for the second time, you could, in theory, send them an application that, when launched, displays the text and erases itself from the disk at the same time. (In Unix-like operating systems, you can erase a file that is in use and it will be removed after the last application using it ends or closes the file.) After they quit from the application, the application itself would be gone.
However, it's still possible that they will run the application and notice this side effect before giving you back the CD, in which case they might save another copy of it. Here are two ways to avoid this:
1. Have the application create a Startup Item that will run at the next restart and then delete the application (and the Startup Item). They are less likely to discover this behavior before giving the CD back.
2. Instead of having the application delete itself, have it check for the CD and not run if it is not present. That way, once they give the CD back, the application is still on their hard disk but is useless. Of course, if they figure this out, they might copy the CD!
In all cases, the text should be built into the application, possibly in an encoded way, so that it can't be extracted from the application files directly.
Another method you could use would be to have the program set to expire on a certain date. If the system date was after that date, it would produce a misleading error message instead of displaying the text. That way they wouldn't think to set their clock back.
All of this is probably more trouble (and programming) than you had in mind, right? Overall, I think an easier solution would be web based, where you send them to a URL that displays the text (maybe after a password prompt) and works only once.
Assuming that they give you the CD back before they try opening the file for the second time, you could, in theory, send them an application that, when launched, displays the text and erases itself from the disk at the same time. (In Unix-like operating systems, you can erase a file that is in use and it will be removed after the last application using it ends or closes the file.) After they quit from the application, the application itself would be gone.
However, it's still possible that they will run the application and notice this side effect before giving you back the CD, in which case they might save another copy of it. Here are two ways to avoid this:
1. Have the application create a Startup Item that will run at the next restart and then delete the application (and the Startup Item). They are less likely to discover this behavior before giving the CD back.
2. Instead of having the application delete itself, have it check for the CD and not run if it is not present. That way, once they give the CD back, the application is still on their hard disk but is useless. Of course, if they figure this out, they might copy the CD!
In all cases, the text should be built into the application, possibly in an encoded way, so that it can't be extracted from the application files directly.
Another method you could use would be to have the program set to expire on a certain date. If the system date was after that date, it would produce a misleading error message instead of displaying the text. That way they wouldn't think to set their clock back.
All of this is probably more trouble (and programming) than you had in mind, right? Overall, I think an easier solution would be web based, where you send them to a URL that displays the text (maybe after a password prompt) and works only once.
i got a cd that had preview pictures(real pictures you had to pay for) for some event. Once you placed the cd in the computer (OSX or XP) it would note the date. after a certain time it would erase the cd. i have no clue how they did it though.....
wow
This is probably the coolest topic I've encountered today (besides the Bush vs. Kerry debate, of course).
This is probably the coolest topic I've encountered today (besides the Bush vs. Kerry debate, of course).
The best way to do this, from a programmers prospective, is to create a program that displays the text you want in a way that the text can not be copied or selected. If it's a Word document, pretty much out of luck here. If it's plain text, RTF, or HTML you can do it. But this obviously requires programming...
If you wanted it to "self destruct" in X days, it would need to keep track of the date when it was opened, and then next time it launches, check that original date (hidden somewhere on the user's machine) with current date. This would work just like shareware/demo apps.
The only other good way I can see to do this is to put it on a floppy disk because floppies are writable and you can delete it directly from floppy
If you wanted it to "self destruct" in X days, it would need to keep track of the date when it was opened, and then next time it launches, check that original date (hidden somewhere on the user's machine) with current date. This would work just like shareware/demo apps.
The only other good way I can see to do this is to put it on a floppy disk because floppies are writable and you can delete it directly from floppy
im sure some dumass would try that with their regular cdrom drive...Counterfit said:Except it would burn and not explode. Actually, that would be just as effective, and much safer. Less shrapnel
Holy Thread ressurection, Batman. 2004 !?!
In order to answer your question -- like the answers above, it would require custom programming to hide the data files(s) within some sort of structure, and then only make it visible if certain conditions are met - such as password and date.
The problem you have is that once data is visible, it can always be copied one way or another (Screenshots off the monitor, for example. Or a recording to cassette tape off of the headphones output. Resetting the computer's system date to a date in the past. Etc.) Nothing is completely secure.
In order to answer your question -- like the answers above, it would require custom programming to hide the data files(s) within some sort of structure, and then only make it visible if certain conditions are met - such as password and date.
The problem you have is that once data is visible, it can always be copied one way or another (Screenshots off the monitor, for example. Or a recording to cassette tape off of the headphones output. Resetting the computer's system date to a date in the past. Etc.) Nothing is completely secure.
Thanks for the reply. It seems more complicated than i thought, the good thing is that the person i want to send the file to is not smart enough to figure out the date roll back or the screen snapshot. so im not overly concerned with aspect. what would you use to write the script, a word program or is there another way to render the thumb drive useless after a date stamp?
Bump?
Sorry to revive such a painfully old thread that has already randomly been bumped back into relevance once. It seems like it has some sort of three year cycle: 2004, 2007, 2010. I do hope I get a reply before 2013 though
The reason I'm posting is because I would like to know how to create a file that is rendered useless after a certain point of time. My reason is that I'm making some music for an unknown client who cannot be trusted. I want to send delivery drafts of the song for them to sample, but I don't want them to be able to use the clip after a certain period of time so that I can ensure they pay me for the final draft.
So far the best solution I have come up with is a self-destructing file. If anyone has any better solutions (e.g. somehow hosting the clip online with reduced permissions) then I would love to hear those too. I don't need financial advice (e.g. make them pay you upfront / use a third party to manage the payment) but any technical advice would help.
Thanks!
Sorry to revive such a painfully old thread that has already randomly been bumped back into relevance once. It seems like it has some sort of three year cycle: 2004, 2007, 2010. I do hope I get a reply before 2013 though
The reason I'm posting is because I would like to know how to create a file that is rendered useless after a certain point of time. My reason is that I'm making some music for an unknown client who cannot be trusted. I want to send delivery drafts of the song for them to sample, but I don't want them to be able to use the clip after a certain period of time so that I can ensure they pay me for the final draft.
So far the best solution I have come up with is a self-destructing file. If anyone has any better solutions (e.g. somehow hosting the clip online with reduced permissions) then I would love to hear those too. I don't need financial advice (e.g. make them pay you upfront / use a third party to manage the payment) but any technical advice would help.
Thanks!
Play them the samples via telephone or deliver them at much lower bitrate than would be useful for the deliverable.
You could probably find a way to stream it online as Flash the can only be played from your site, but if they really want to rip you off they can still capture the audio and get around whatever means of DRM you impose.
B
another need (well, desire) for self destruct
I have a file on my HD that only I know is there.
And it's pretty well hidden.
And it's encrypted.
Nevertheless, if something happens to me I do not want anyone in the future to stumble across this file.
I'm thinking that if I can access it every month and bump the self-destruct date by another month, that would come satisfactorily close to guaranteeing that nobody else will ever see it. [Hmmm. Something puts me in the hospital for a while and I don't get back to my computer within 30 days. OK, SIX months.]
So it only has to be wiped from my HD by this hypothetical self-destruct mechanism. (It is not being backed up to Time Machine, but rather being manually backed up to a separate HD.)
Any thoughts? (Aside from snarky comments about the contents of my file?)
I have a file on my HD that only I know is there.
And it's pretty well hidden.
And it's encrypted.
Nevertheless, if something happens to me I do not want anyone in the future to stumble across this file.
I'm thinking that if I can access it every month and bump the self-destruct date by another month, that would come satisfactorily close to guaranteeing that nobody else will ever see it. [Hmmm. Something puts me in the hospital for a while and I don't get back to my computer within 30 days. OK, SIX months.]
So it only has to be wiped from my HD by this hypothetical self-destruct mechanism. (It is not being backed up to Time Machine, but rather being manually backed up to a separate HD.)
Any thoughts? (Aside from snarky comments about the contents of my file?)
If it is encrypted anyway it doesn't matter if anybody finds it does it.
Got me wondering what the file is though
Because this is a file on your computer, instead of a file you want to distribute to someone else then destroy on their computer, you have an easier time.
You can create an Automator Application to delete the file based on some condition, then create a cron job to periodically run the app. You can also tie an Automator app to an iCal Alert.
I agree with the previous poster that encrypting the file sort of renders this moot.
To take encryption to the next level though, TrueCrypt has an option where you can create a hidden volume (for lack of a better term) within an encrypted volume. So you first have to decrypt the 'outer' container, then you have to know that the 'inner' container is there before you can decrypt and mount it. You would usually put some innocent files into the 'outer' container so that it seems like the intruder has gotten to your goodies and doesn't think to look for a second volume.
You can create an Automator Application to delete the file based on some condition, then create a cron job to periodically run the app. You can also tie an Automator app to an iCal Alert.
I agree with the previous poster that encrypting the file sort of renders this moot.
To take encryption to the next level though, TrueCrypt has an option where you can create a hidden volume (for lack of a better term) within an encrypted volume. So you first have to decrypt the 'outer' container, then you have to know that the 'inner' container is there before you can decrypt and mount it. You would usually put some innocent files into the 'outer' container so that it seems like the intruder has gotten to your goodies and doesn't think to look for a second volume.