I have some PDF documents and I'd like to check them for possibile data corruption, even if I'm able to display them without problems. I don't really know if PDF documents store an embedded checksum string for this kind of purposes. My operating system of choice is GNU/Linux. Thanks.
Browsing through PDF Reference sixth edition (2006), it appears that PDF files do not have an overall checksum, though embedded files within the PDF (similar to attachments in an email message) may optionally have an MD5 hash.
You should therefore archive your PDFs in a container which supports error detection / correction. For example, a zip file, or optical media (CD-R etc).