This article describes Transparent Data Encryption for Base Database Service.

All user-created tablespaces in a DB system database are encrypted by default, using Transparent Data Encryption (TDE).

• On a 1- or 2-node RAC DB system, you can use the TDE commands to update the master encryption key for a database.
• You must create and activate a master encryption key for any PDBs that you create. After creating or plugging in a new PDB on a 1- or 2-node RAC DB System, use the dbcli update-tdekey command to create and activate a master encryption key for the PDB. Otherwise, you might encounter the error ORA-28374: typed master key not found in wallet when attempting to create tablespaces in the PDB. In a multitenant environment, each PDB has its own master encryption key which is stored in a single keystore used by all containers.
• For version 12c databases, if you don’t want your tablespaces encrypted, you can set the ENCRYPT_NEW_TABLESPACES database initialization parameter to DDL.