|I believe that if you use one of the free PDF converters (e.g. CutePDF) that install as a printer subsystem, the PDF created by the app can not be edited. You could create your PDF using Adobe Acrobat X and then "print" it to CutePDF prior to distribution.|
CutePDF is free (as are others of like kind) so it can't hurt to try it.
That said, I don't know if there is any document that "absolutely CANNOT be edited or tampered with".
I don't have a PDF creator app on my system but I do have CutePDF. I printed this web page to CutePDF to create a PDF doc. I then inserted the PDF as an object into PowerPoint and added a text box over some of the "text" from your post - using different words, of course. I then printed it back out to CutePDF.
If I spent more than the 30 seconds I spent doing it, I bet I could create a PDF that you couldn't tell was a "tampered with" copy of the original.
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