Getting LUKS headless disks IDs

I hope that the description of what I try to do is clear enough.

Till now all my disks were LUKS encrypted using keys. The thing is that they still have in the header information about encryption, so I was thinking to separate also the header.

The process of encrypting/decrypting is somehow automatic - I have a list will all disk UUID (I use blkid to get them) and from there I get the appropriate key for the disk.

The problem is I can't figure it out how to do that with headless disks as there is no UUID in blkid output for them. Do you have any suggestion?