A Distribution KDM (DKDM) is technically identical to a regular KDM.
The difference is that it targets another mastering station instead of a cinema server.
You can generate a DKDM with easyDCP KDM Generator. The procedure is identical to generating a regular KDM.
The other way around is also possible with easyDCP. Your distributor can generate a DKDM to your easyDCP Player+ or easyDCP Creator+ public certificate (they each have theire own certificate). easyDCP Player+ or easyDCP Creator+ are then able to open the encrypted DCP.
Starting with version easyDCP Player+ 1.3 the DCP can be exported and loaded into easyDCP Creator.
This is explained in the section: I have an existing DCP. Is there a way to import the DCP into easyDCP Creator?".
Please check also: I have an existing DCP. Is there a way to import the DCP into easyDCP Suite?
How to generate KDMs and DKDMs in easyDCP: