How to make a pdf expire

A vendor is telling me that they would give me a script to make pdf expire. Is this legal/possible?

How should i approach them to ask about further detials?

I doubt that it's just a script, it's probably a full blown application. I don't see any reason why this would not be legal (assuming they are not using some cracked software). To really "expire" a PDF, you need a server based solution: The client needs to contact the server in order to find out if the PDF document should still be readable. Otherwise it's possible to make an expired document accessible again by just setting the clock back.

Ask them what system they are using, and how reliable it is (e.g. if it would be immune against playing tricks with the clock). Ask them if the people who are opening the document need any special software (e.g. Acrobat or Reader plug-ins). For a reliable DRM solution you need to install software on the client's machine. Ask them what the fee schedule is (e.g. if you have to pay for every single document that you distribute).

JavaScript is not a tool to implement document security: I can rename the JavaScript plug-in so that JS is not available when I restart Acrobat, and all your security mechanisms will fail. To avoid that, you could hide the "real" content of the file behind large forms elements that you remove when with JavaScript when it's OK to view the file, but this can also be worked around by removing the forms plug-in.
JavaScript is the wrong tool for this job. You need a full fledged DRM solution, there is no way around this.

From the questioner's responses, a fully fledged DRM system may not be practical. The Javascript solution will work for most users except those with exceptional depth of knowledge in Acrobat and its scripting support. The fact is, almost any DRM system can also be subverted with the appropriate tools or software -- that doesn't make them bad solutions. It all depends on the level of protection you're looking for.

There is a difference in circumventing a real DRM solution (like Adobe LifeCycle Document Security - http://www.adobe.com/products/server/securityserver/main.html) and a JavaScript solution. The first one is designed with document security in mind, JavaScript was never designed for that. There is also a reason for the difference in price: You get one for free, and the other one consts an arm and a leg.

I did not get the impression that the asker was interested in a system that can be easily broken. The only requirement I see is "cheap", which I interpreted as inexpensive.

The vendor sent me a sample but it doesnt seem to work. While I understood from mjlodge's example of how this can be accomplished to make pdf expire, i am still not sure how they can use the scrip to make document viewable only a certain number of times?

Also, is there an ebook or any other solution to do the same? I dont mind spending upto $200, but anything more than that would be a killer for a small experimental .

You could put a hidden field in the PDF and use it to store a counter of the number of times the document has been opened. Make it so the user can't change it, of course. khremer is quite right that this is not foolproof, but it's a good cheap solution.

HI, sambha03

Would like to share the sample script ? I have such needs too but can aford to buy DRM solution. Many thanks.

Oh, my email is sobad200301@yahoo.com. Thanks again.

eugene_liu: Like i said the vendor sent me a sample but it doesnt seem to work. I never asked them for the script since the sample never worked.

You may take a look at free third party solutions like this one
PDF Security OwnerGuard

You may take a look at free third party solutions like this one
PDF Security OwnerGuard