PDF Files Manipulation Detection

[Kawther26460547c677]

Hello, 

I am facing a problem on the inability to verify if a pdf file reaching to me is truly genuine. So how can i detect if a pdf file is amended or manipulated? and how can i determine the manipulation? 

[Test Screen Name]

You must apply a digital signature using a certificate you own. Acrobat can detect whether the file has been modified since you created it (because any change does not match the certificate).

[Kawther26460547c677]

The pdf files are not created by me, they are created by others!! How can I apply a digital signature?

[Test Screen Name]

Are you hoping to detect whether the file was modified BEFORE you got it? No hope of that at all, unless it was signed by someone else. 

[try67]

There is an entire science behind this kind of thing, called forensic document analysis, but it's not a trivial task. You will need some advanced (and often expensive) tools to be able to detect such things. PDF files can contain a sort of "cache" of previous versions of themselves, or a record of revisions done to them, so in theory it's possible to detect that a file has been modified after its initial creation, but it depends on many factors.