How to verify PDF or Excel files are not corrupted

I have a slight dilema, we're about to hire an intern and his first job will be to go through roughly 200 PDFs, 40 Adobe Photoshop files, around 300 word documents and 120 excel files to verify that they are not corrupted and whether they have any protection on them (password).

I don't want to bore the kid, so I was th开发者_C百科inking of automating it. I'm wondering what I can do to verify whether the PDF files are valid and whether they have any password without having to open them in Acrobat.

Is there a BOM I can look for or is PDF parsable enough to use something like iTextSharp? As for the Office files, I'm hoping Office Interop can look at the file and tell me via the object model? Photoshop I'm not sure is even possible, so he'll have to do that manually.

This will be written as a small WinForms application in C# or Delphi.NET (our language here).

Any thoughts?

You could automate printing them out or converting to image and see which ones do not work