Document management of academic qualifications using any BPM software

I need to handle academic documents, with BPM software (any) .Generate metadata for them. Create management, central and historical repositories. Convert from word to "sealed" pdfs. Convert "word" documents (or scanned documents) to sealed pdfs, with metadata generated in secure repositories. Create an approval flow for those documents (3 or 4 persons). There are not many documents. Only 4 users who manage and approve or modify (there must be a record of all of them)