During the application process you will be asked, if you would like to have your certificate publicly available. Answering Yes means, that anybody can search for your certificate at a DFN directory. That directory is not browsable, not scannable, and always requires the exact name or email address of the certificate's owner. With a found certificate, your may immediatly start an encrypted communication with the certificate's owner.

Choosing No means, that you need to exchange your certificates in an unencrypted communication prior to starting an encrypted communication.

You may withdraw the publication of your certificate at any time, but a later publication consent is not realisable.