The Portable Document Format, better known as PDF, is one of
the most widely used document formats worldwide, and in order to
ensure information confidentiality, this file format supports
document encryption. In this paper, the authors analyze PDF
encryption and show two novel techniques for breaking the
confidentiality of encrypted documents.
Read more https://packetstormsecurity.com/files/154692/paper-pdf_encryption-ccs2019.pdf
