PDF with expire date

Questions
1

Hello,

I have a question. One of the current biggest concerns with privacy is sharing information through the PDF format. Sending over information to a different person/organisation removes you the control of that information. The only option is to hope the receiving party deals with the information responsibly. To my surprise does not happen at all most of the time.

The biggest concerns is that PDF files you can keep on a computer for 120+ years with who knows who has access to it.

Is there a way or alternative format to let information expire after certain amount of time?

I found this Locklizard but I was wondering if there are some experts on the issue.

Presumably something that works in Linux. According to what I read you cannot let PDFs expire because the only way to do it is through JavaScript. But you can just turn off JavaScript in PDF readers and still open the file.

2

This is an issue with data of any format, not just PDF.

It’s impossible, both by definition and practically, to retain exclusive control over data while giving a copy of it away.

However it is possible to show data to people using your own devices. This is what movie theaters, concerts etc attempt to achieve.

There are disappearing messages in Signal and other chat apps, akin to the expiry dates concept, but this is a compromise that erodes exclusive control. Any recipient can save attachments and take screenshots of messages they receive, or use unofficial clients that don’t delete messages in spite of any disappearing message setting.

3

Yep, even with unhackable DRM you could use a different camera.

Unless… It streams straight to your brain

4

Physical medium.

5

Filen has an option called “Public Link”, which allows you to share files in read-only format (if you disable the download button). You can also add a password and set an expiration date for the link itself. Sure, people could still take screenshots of the file, but that’s unavoidable anyway.

6

Yeah… I’m afraid that the problem you’re referencing is a result of how computers work in general :sweat_smile:

Literally the only way to guarantee that would be malware and well… Don’t do that.

7

Hi All,

Thanks for all the replies. I know for AI they are trying to develop a new format that replaces PDF/DOCX. So maybe there will come a privacy centred format as well in the future.

Today I saw in Tuta’s blog that there is a French company called Cryptpad which allows documents to be shared and deconstructed after some time.

Full encryption, opensource, EU based company. I will try to use them to share sensitive information.

maybe useful for other people as well