Oracle Database 10g introduced Transparent Data Encryption (TDE), which enabled you to encrypt columns in a table. The feature is called “transparent” because the database takes care of all the encryption and decryption details. In Oracle Database 11g, you can also encrypt an entire table space. In fact, table space encryption helps you get around some of the restrictions imposed on encrypting a column in a table through the TDE feature. For example, you can get around the restriction that makes it impossible for you to encrypt a column that’s part of a foreign key or that’s used in another constraint, by using table space encryption.
Restrictions on Table space Encryption
You must be aware of the following restrictions on encrypting table spaces. You
Can’t encrypt a temporary or an undo table space.
Can’t change the security key of an encrypted table space.
Can’t encrypt an external table.
As with TDE, you need to create an Oracle Wallet to implement table space encryption. Therefore,let’s first create an Oracle Wallet before exploring how to encrypt a table space.