PDF digital signature is it for page or whole document?

Is the PDF digital signature for a page or for an entire document? Can a page be signed? Although the signature is generally put on a particular page of the file, the whole document is in fact signed. Nevertheless, PDF format supports so-called ‘incremental updating’ strategy that permits to add pages to the file without […]

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PDF Font encoding why can’t I copy text from a PDF?

After transforming a PDF file, I can not copy the text from it anymore. All I get are unreadable characters which make no sense whatsoever. qpdf (by Jay Berkenbilt) to evaluate the file. pdfid.py and pdf-parser. py (by Didier Stevens) to evaluate more. PDFlib’s TET (text extraction tool) to extract and try text. PDFlib’s Font […]

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