CREATE DATABASE ENCRYPTION KEY (Transact-SQL)

WITH ALGORITHM = { AES_128 | AES_192 | AES_256 | TRIPLE_DES_3KEY }

Specifies the encryption algorithm that is used for the encryption key.

ENCRYPTION BY SERVER CERTIFICATE Encryptor_Name

Specifies the name of the encryptor used to encrypt the database encryption key.

ENCRYPTION BY SERVER ASYMMETRIC KEY Encryptor_Name

Specifies the name of the asymmetric key used to encrypt the database encryption key. In order to encrypt the database encryption key with an asymmetric key, the asymmetric key must reside on an extensible key management provider.

A database encryption key is required before a database can be encrypted by using Transparent Database Encryption (TDE). When a database is transparently encrypted, the whole database is encrypted at the file level, without any special code modifications. The certificate or asymmetric key that is used to encrypt the database encryption key must be located in the master system database.

Database encryption statements are allowed only on user databases.

The database encryption key cannot be exported from the database. It is available only to the system, to users who have debugging permissions on the server, and to users who have access to the certificates that encrypt and decrypt the database encryption key.

The database encryption key does not have to be regenerated when a database owner (dbo) is changed.

Requires CONTROL permission on the database and VIEW DEFINITION permission on the certificate or asymmetric key that is used to encrypt the database encryption key.

For additional examples using TDE, see Transparent Data Encryption (TDE) and Enable TDE Using EKM.

The following example creates a database encryption key by using the AES_256 algorithm, and protects the private key with a certificate named MyServerCert.

USE AdventureWorks2012;
GO
CREATE DATABASE ENCRYPTION KEY
WITH ALGORITHM = AES_256
ENCRYPTION BY SERVER CERTIFICATE MyServerCert;
GO

Reference

Concepts