One of leading standards to encrypt communication between application server and DB server is by using Transparent Data Encryption (TDE):

https://docs.oracle.com/en/database/oracle/oracle-database/19/asoag/introduction-to-transparent-data-encryption.html#GUID-62AA9447-FDCD-4A4C-B563-32DE04D55952

Companies are having this technology as bare minimum security.

It's not officially supported by MySQL and PostgreSQL, but officially supported by Oracle.

Need to have some options on how to run TDE in Zabbix.