What is Storage Encryption?
Storage encryption involves encrypting data while it passes to storage devices, such as individual hard disks, tape drives, or the libraries and arrays that contain them. Using storage level encryption along with database and file encryption goes a long way toward offsetting the risk of losing your data. Like network encryption, storage encryption is a relatively blunt instrument, typically protecting all the data on each tape or disk regardless of the type or sensitivity of the data.
Although using storage encryption is a good way to ensure your data is safe by default in case it is lost, adopting a more granular approach and encrypting at the level of individual files, volumes, or columns in a database may be necessary, particularly if data is shared with other users or is subject to specific audit requirements.