恢复SQL中的加密备份

Question

I use this code

USE master;  
GO  
CREATE MASTER KEY ENCRYPTION BY PASSWORD = '1234';  
GO  
CREATE CERTIFICATE Cer
   WITH SUBJECT = 'Hello';  
   GO

and then backup database with this code

backup database Temp to disk = 'D:\Backup\temp.bak'
 WITH  
  COMPRESSION,  
  ENCRYPTION   
   (  
   ALGORITHM = AES_256,  
   SERVER CERTIFICATE = Cer
   ),
  STATS = 10

now I can not restore it to another server i create this master key on another server but it dose not work

Answer 1

The master key is used to protect the certificate used for the backup encryption. The certificate is unique - specifying same name for executing the CREATE CERTIFICATE statement creates different certificate.

If this was not true, everyone with access to your backup would be able to decrypt it.

So, you need to export your certificate:

-- Backup the certificate
BACKUP CERTIFICATE BackupEncryptCert TO FILE = 'H:\MSSQL\Backup\Keys\BackupEncryptCert.cer'
    WITH PRIVATE KEY (FILE = 'H:\MSSQL\Backup\Keys\BackupEncryptCert.PrivateKey.pvk', 
    ENCRYPTION BY PASSWORD = 'doodle$7')
GO

and then to create it on the new instance:

-- Restoring a certificate from existing certificate backup
CREATE CERTIFICATE BackupEncryptCert
    FROM FILE = 'H:\MSSQL\Backup\Keys\BackupEncryptCert.cer'
    WITH PRIVATE KEY (FILE = 'H:\MSSQL\Backup\BackupEncryptCert.PrivateKey.pvk',
    DECRYPTION BY PASSWORD = 'doodle$7')
GO

Then you will be able to restore your encrypted backup.