How to: Create a Database Master Key
The database-level cryptographic features in SQL Server rely on a database master key. This key is not generated automatically when the database is created; it must be created by the system administrator. It is only necessary to create the master key once per database.
To create a database master key
In Query Editor, connect to the database by executing the following Transact-SQL command: USE <database name> ; GO.
Choose a password for encrypting the copy of the master key that will be stored in the database.
Execute the following Transact-SQL command: CREATE MASTER KEY ENCRYPTION BY PASSWORD = '<password>' ; GO
You should immediately back up the new master key. For more information, see How to: Back Up a Database Master Key.