DATA ENCRYPTION
Protect customer data at-rest and in-transit in a way that allows customers to meet their security and compliance requirements for cryptographic algorithms and key management.
https://docs.oracle.com/en-us/iaas/Content/Security/Concepts/security_overview.htm

A listener is an entity that checks for connection requests. The load balancer listener listens for ingress client traffic using the port you specify within the listener and the load balancer's public IP.
https://docs.oracle.com/en-us/iaas/Content/GSG/Tasks/loadbalancing.htm
To create a listener:
On your Load Balancer Details page, click Listeners.
Click Create Listener.
Enter the following:
Name: Enter a friendly name. Avoid entering confidential information.
Protocol: Select HTTP.
Port: Enter 80 as the port on which to listen for incoming traffic.
Backend Set: Select the backend set you created.
Click Create.

https://docs.oracle.com/en/database/other-databases/essbase/21/essad/create-vault-and-secrets.html