It only has security to allow editing / copying / and in some cases, opening at all.
An OCR package will simply read the data from the file and create a Word File or whatever you told it to OCR into. Then you can work with the data in the new document. You could possibly screen shot the open doc too into a tiff format to OCR also if you just wanted.
We use eCopy at work, and it OCRs from PDF files (it uses Omni 8 as its underlying scan software).