Hi Wale,
It is already possible to enable encryption between your Cassandra nodes (Cassandra should use then port 7001 instead of 7000 by default). The configuration can be found for this in the yaml file (C:\Program Files\Cassandra\conf\cassandra.yaml) under 'server_encryption_options'.
From 10.1.3 feature release it will be possible to set up an encrypted connection between DataMiner and Cassandra. Then you will need to look at the 'client_encryption_options' settings on your Cassandra nodes. And you will most likely need to uncomment this setting: 'native_transport_port_ssl: 9142'.

For more details:
SSL encryption (datastax.com)

Documentation (apache.org)