volume-key binary package in Ubuntu Bionic s390x

 This package provides a command-line tool for manipulating storage volume
 encryption keys and storing them separately from volumes.
 .
 The main goal of the software is to allow restoring access to an encrypted
 hard drive if the primary user forgets the passphrase. The encryption key
 back up can also be useful for extracting data after a hardware or software
 failure that corrupts the header of the encrypted volume, or to access the
 company data after an employee leaves abruptly.

Source package