converting to PDF/A

First thing to say is that PDF/A is not "more secure" - in fact it's intentionally designed _not_ to be secured at all. You can apply encryption and rights management to normal (vanilla) PDF files, but doing that to a PDF/A file is prohibited. Also, PDF/A files are larger than their vanilla counterparts due to the requirement to embed everything. They are designed for archival storage of documents (contracts, legal paperwork, etc.), not for distribution of periodical material to a large audience. Those of us who work with PDF/A tend to give the same advice - don't use it unless you really have to!

If you want a secured version of your publication to distribute, then export a vanilla PDF file from InDesign and apply permissions security to restrict editing, printing etc. as required, but don't bother making the file standards-compliant. The PDFs exported from CS2 are not as efficiently-packed as they are in the current versions (even an upgrade to CS3 will make a huge difference) but they're syntactically correct.

If you have a particular reason for requiring PDF/A, then with ID CS2 you won't be able to create it directly, nor will you ever be able to create the accessible PDF/A-1a version that tends to be specified by federal agencies. InDesign doesn't use Acrobat to export PDF files, it uses an embedded copy of the PDF Library (ID CS2 uses PDFLib 7), and to date this doesn't support PDF/A-1a. Any workflow that uses printing (directly or via PostScript) will make PDF/A-1a impossible as the document structure needs to be parsed to form the accessibility data, so it has to be done by a native plugin (such as the PDFMaker plugin for Microsoft Office that's installed by Acrobat 8 Pro and later).

Acrobat 6 doesn't support PDF/A at all, it simply wasn't around when A6 was written, but you can make a PDF file which follows the same rules even though it isn't tagged as a PDF/A file. There are tutorials on the Learning Center which explain what a PDF/A file is and isn't allowed to contain. Upgrading Acrobat will let you print to PDF/A-1b (the non-accessible version) but InDesign files can't realistically be exported to PDF/A-1a until we get a new version with an updated PDF engine.

Many thanks for your response. When I say 'more secure' what I probably ought to have said was 'more resistant to malicious attack' (important in my line of business = publishing for the computer anti-malware industry) - see http://nakedsecurity.sophos.com/2011/01/24/review-omg-wtf-pdf/ for example. In the security industry PDF/A files are considered to be significantly 'safer' than PDF - effectively, with all the bells and whistles stripped out, the file is less vulnerable to attack.

Thanks again

A file that is truly a PDF/A file doesn't have a number of features that could be used as a vector for malicious behaviour. For that matter, the PDF/X file formats have that exact same characteristic! That having been said, there is nothing that prevents one from labelling a PDF file as PDF/A (or PDF/X) although that file doesn't meet the requirements for same. The only way you can be assured that you have a PDF/A (or PDF/X) file that doesn't have vectors for malicious behaviour and in fact is not corrupted in such a way to launch malicious behaviour is to pass such a file through both anti-virus and PDF preflight functions. Thus, I would strongly disagree with any assertion that a file simply labelled as PDF/A is in any way “safer” than one not so-labelled.

And as pointed out, Acrobat 6 is a four version out-of-date version of Acrobat which does not support PDF/A in any way.

- Dov