Matthias Valvekens, the ISO project leader who led development of ISO 32004, has written a pair of blog posts to explain what ISO 32004 does and does not achieve in leveraging MAC technology for securing encrypted PDF files against tampering.
Non-rectangular links are coming to PDF 2.0! This article offers some background to link technology in PDF and discusses the forthcoming Extension to PDF 2.0.
This post provides users with a quick overview of PDF/A explaining what it is, why it should be used, what is important about it and how to create PDF/A files.