- Adobe offers a 7-days trial of its Acrobat Pro. It's technically free but not terribly useful in the long run.
- LibreOffice can export a file as PDF, but only with 128-bit RC4 encryption. Obsolete.
- PDFMate PDF Converter provides only 40-bit encryption.
- There are various websites I did not even check because uploading unprotected sensitive data to the Internet is the opposite of protection in my opinion.
So, any further ideas?