The Oracle Exadata database machine is known for a lot of features, however, one of the more overlooked features is the ability to make use of some of the hardware accelerated cryptographic features that come with the Intel processors that are in the Exadata storage cells. The Exadata X4-2 is equipped with Intel Xeon E5-2697 v2 processors who do have the AES-NI Intel data protection technology build in to them.
"Advanced Encryption Standard New Instructions (AES-NI) are a set of instructions that enable fast and secure data encryption and decryption. AES-NI are valuable for a wide range of cryptographic applications, for example: applications that perform bulk encryption/decryption, authentication, random number generation, and authenticated encryption."
When there is a need to ensure encryption of data on an Exadata platform you can make use of the Oracle Advanced Security feature Transparent Data Encryption. The Transparent Data Encryption is also extended to the Smart Flash Cache and Hybrid Columnar Compression parts of the Exadata to ensure that there is a full encrypted storage of your data. When doing encryption in a standard way with processors that are unable to directly work with cryptography in the processor itself it might be a performance degradation, due to the fact that the Exadata platform makes use of processors that have AES-NI build in this is no longer an issue.
What Oracle Transparent Data Encryption is doing is protecting your data against data theft on a storage level. Your data files will have to be stored somewhere on a data storage device, in the case of an Exadata these are the storage cells in your exadata. A commonly overlooked fact is that someone could potentially steel those files directly from storage or when they are moved to a backup device.
Transparent data encryption stores all data on storage in an encrypted manner. This however, can be a hughe performance gain when done on non-optimized processors. Due to the fact that Intel has AES-NI Intel data protection technology build in to the processors directly a number of additional layers are removed from the processes that would otherwise be used to encrypt and decrypt the data coming from disk before it can be used by the database.