backup-master-key-transact-sql.md

description	BACKUP MASTER KEY (Transact-SQL)
title	BACKUP MASTER KEY (Transact-SQL) | Microsoft Docs
ms.custom
ms.date	05/24/2022
ms.prod	sql
ms.prod_service	sql-database
ms.reviewer
ms.technology	t-sql
ms.topic	reference
f1_keywords	BACKUP MASTER KEY DUMP_MASTER_KEY_TSQL BACKUP_MASTER_KEY_TSQL DUMP MASTER KEY
dev_langs	TSQL
helpviewer_keywords	BACKUP MASTER KEY statement exporting Database Master Keys encryption [SQL Server], Database Master Key cryptography [SQL Server], Database Master Key backing up master keys [SQL Server] database master key [SQL Server], exporting
author	VanMSFT
ms.author	vanto

BACKUP MASTER KEY (Transact-SQL)

[!INCLUDE SQL Server]

Exports the database master key.

Important

SQL Server 2022 introduces backup and restore support for the database master key to and from an Azure Blob storage. The URL syntax is only available for SQL Server 2022 or later.

Transact-SQL Syntax Conventions

Syntax

BACKUP MASTER KEY TO 
  {
    FILE = 'path_to_file'
  | URL = 'Azure Blob storage URL'
  }   
    ENCRYPTION BY PASSWORD = 'password'  

[!INCLUDEsql-server-tsql-previous-offline-documentation]

Arguments

FILE ='path_to_file'
Specifies the complete path, including file name, to the file to which the master key will be exported. The path may be a local path or a UNC path to a network location.

URL ='Azure Blob storage URL'
Applies to: SQL Server 2022 or later
Is the URL for your Azure Blob storage, in the format similar to https://<storage_account_name>.blob.core.windows.net/<storage_container_name>/<backup_file_name>.bak.

ENCRYPTION BY PASSWORD ='password'
Is the password used to encrypt the master key in the file. This password is subject to complexity checks. For more information, see Password Policy.

Remarks

The master key must be open and, therefore, decrypted before it's backed up. If it's encrypted with the service master key, the master key doesn't have to be explicitly opened. But if the master key is encrypted only with a password, it must be explicitly opened.

We recommend that you back up the master key as soon as it's created, and store the backup in a secure, off-site location.

If you're using SQL Server 2022 or later, and want to back up the database master key to an Azure Blob storage, the following prerequisites apply:

1. Have an Azure storage account.

2. Create stored access policy and shared access storage.

3. Create a SQL Server credential using a shared access signature.

   For more information, see Tutorial: Use Azure Blob Storage with SQL Server.

Permissions

Requires CONTROL permission on the database.

Examples

The following example creates a backup of the AdventureWorks2012 master key to a file. Because this master key isn't encrypted by the service master key, a password must be specified when it's opened.

USE AdventureWorks2012;  
OPEN MASTER KEY DECRYPTION BY PASSWORD = 'sfj5300osdVdgwdfkli7';  
BACKUP MASTER KEY TO FILE = 'c:\temp\AdventureWorks2012_master_key'   
    ENCRYPTION BY PASSWORD = 'sd092735kjn$&adsg';  
GO   

The following example creates a backup of the AdventureWorks2012 master key to an Azure Blob storage. Because this master key isn't encrypted by the service master key, a password must be specified when it's opened.

USE AdventureWorks2012;  
OPEN MASTER KEY DECRYPTION BY PASSWORD = 'sfj5300osdVdgwdfkli7';  
BACKUP MASTER KEY TO URL = 'https://mydocsteststorage.blob.core.windows.net/mytestcontainer/AdventureWorks2012_master_key.bak'  
    ENCRYPTION BY PASSWORD = 'sd092735kjn$&adsg';  
GO   

See also

CREATE MASTER KEY (Transact-SQL)
OPEN MASTER KEY (Transact-SQL)
CLOSE MASTER KEY (Transact-SQL)
RESTORE MASTER KEY (Transact-SQL)
ALTER MASTER KEY (Transact-SQL)
DROP MASTER KEY (Transact-SQL)
Encryption Hierarchy
BACKUP SYMMETRIC KEY