On 2020-03-02 05:25 AM, M Henri Day wrote:
I'm not a Mac user myself, but according to Jack Wallen at *Tech Republi*c ( https://www.techrepublic.com/article/how-to-sign-libreoffice-6-documents-with-gnupg/), if one has installed a PGP tool for MacOS (he suggests GPG Suite), one can sign documents by following the procedures outlined in the article....
Can the OP use GPG? Or do they need X.509? Typically, X.509 is used between businesses.