Enterprises typically employ TDE to solve compliance issues such as PCI DSS which require the protection of data at rest.
[citation needed] Oracle TDE addresses encryption requirements associated with public and private privacy and security mandates such as PCI and California SB 1386.
SQL Server utilizes an encryption hierarchy that enables databases to be shared within a cluster or migrated to other instances without re-encrypting them.
The hierarchy consists of a combination of symmetric and asymmetric ciphers:[4] During database backups, compression occurs after encryption.
This presents a potential security issue because the stored keys can be directly recovered from a live system or from backups and used to decrypt the databases.