The delete operation on the Trustee key provider is a "soft delete", meaning that is possible to "undelete" the key. It is also possible to "purge" the key to delete it permanently. Because these operations are not part of the standard Hadoop key provider API, they are not currently exposed through Hadoop KeyShell (hadoop key). However, you can call these operations directly via the Trustee key provider REST API.
See the examples below.