oracle database native  network encryption

vi  /u01/app/oracle/product/19c/db_1/network/admin/sqlnet.ora

# sqlnet.ora Network Configuration File: /u01/app/oracle/product/19c/db_1/network/admin/sqlnet.ora

# Generated by Oracle configuration tools.

NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)

SQLNET.ENCRYPTION_SERVER = REQUIRED
SQLNET.ENCRYPTION_TYPES_SERVER = (AES256)
SQLNET.CRYPTO_CHECKSUM_SERVER = REQUIRED
SQLNET.CRYPTO_CHECKSUM_TYPES_SERVER = (SHA512)

#

Ideally, on the client side we should add these too:
SQLNET.ENCRYPTION_CLIENT = REQUESTED
SQLNET.ENCRYPTION_TYPES_CLIENT = (AES256)
SQLNET.CRYPTO_CHECKSUM_CLIENT = REQUESTED
SQLNET.CRYPTO_CHECKSUM_TYPES_CLIENT = (SHA512)