Transparent Data Encryption
Transparent Data Encryption (often abbreviated to TDE) is a technology employed by both Microsoft and Oracle to encrypt database files. TDE offers encryption at file level. TDE solves the problem of protecting data at rest, encrypting databases both on the hard drive and consequently on backup media. Enterprises typically employ TDE to solve compliance issues such as PCI DSS.
Microsoft offers TDE as part of its Microsoft SQL Server 2008, SQL Server 2008 R2 and SQL Server 2012. TDE is only supported on the Evaluation, Developer, Enterprise and Datacenter versions of Microsoft SQL Server. SQL TDE is supported by Hardware Security Modules from Townsend Security and SafeNet, Inc.
Oracle requires the Advanced Security Option for Oracle 10g and 11g to enable TDE. Oracle TDE addresses encryption requirements associated with public and private privacy and security mandates such as PCI and California SB 1386. Oracle Advanced Security TDE column encryption was introduced in Oracle Database 10g Release 2. Oracle Advanced Security TDE tablespace encryption and support for Hardware Security Modules (HSM) were introduced with Oracle Database 11gR1. Keys for TDE can be stored in an HSM to manage keys across servers, protect keys with hardware, and introduce a separation of duties.
The same key is used to encrypt columns in a table, regardless of the number of columns to be encrypted. These encryption keys are encrypted using the database server master key and are stored in a dictionary table in the database.
- Enterprise Security Features Supported by Microsoft SQL Server 2008 R2 Editions
- Security Features Supported by Microsoft SQL Server 2012 Editions
- Understanding Transparent Data Encryption (TDE) (Microsoft)
- Using Transparent Data Encryption in Oracle Database 11g
- Oracle Transparent Data Encryption best practices
- TDE column encryption and TDE tablespace encryption in Oracle Database 11gR1