This document provides information about using PKCS #11 libraries to configure our HSMs with Oracle Database 12c Transparent Data Encryption (TDE). For additional questions related to your HSM, see the user guide.

From the Oracle documentation website: Transparent data encryption (TDE) enables you to encrypt sensitive data, such as credit card numbers, stored in table columns. Encrypted data is transparently decrypted for a database user who has access to the data. TDE helps protect data stored on media if the storage media or data file gets stolen.