You use an ADD or UPDATE control statement to supply a value to KGUP. The program receives the value, enciphers the value under a master key variant, and places the value in a CKDS entry. The value that you supply may be in clear form or it may be encrypted under a transport key. The statement that contains the value may be sent from another system. The other system sends the value to create a key on your system. This key is the complement of a key that was generated on the other system.
You can supply a transport key value to KGUP from a system that does not use control vectors. You use the key for key exchange with that system. KGUP places the key into the CKDS with an indication that the key is to be used without control vectors.