I've recently upgraded our server from CentOS 6 to CentOS 7 and I am having issues getting pdf encryption working on it.
On CentOS 6 I installed libgcj and then the pdftk package. I could then encrypt pdfs using
/usr/sbin/pdftk pdfName.pdf output pdfEncrypted.pdf owner_pw 123 user_pe 123
I know I cannot install pdftk on CentOS 7 because it does not support libgcj but is there an alternate way to achieve what I need?