SQL Server – Transparent Data Encryption – TDE
Transparent data encryption (TDE) is a new feature in SQL Server 2008 that can be used to encrypt the storage of an entire database. TDE encrypts the data using a symmetric key called the database encryption key.
Protect the database encryption key by using an asymmetric key stored in an extensible key management (EKM) module. EKM provider needs to be contacted to get a HSM device. According to Microsoft, implementation of TDE does not have any impact on the through-put to the database in the SQL Server 2008.
1. MSDN Online.