Requirement for SQL Server Backup Encryption

Database Master Key (DMK)
Certificate with private Key

Create DMK

Check if Database Master Key (DMK) using following
command
SELECT * FROM master.sys.symmetric_keys;

If the ##MS_DatabaseMasterKey## row does not exist, use the following query to create it:

CREATE MASTER KEY ENCRYPTION BY PASSWORD='StrongPassword';

Create Certificate

USE master
GO
CREATE CERTIFICATE DBBackupEncryptionCertificate
WITH SUBJECT = 'This Cert will be used in db backup encription';
GO

Backup Database

Now you are ready to backup the database

BACKUP DATABASE [AdventureWorks]
TO DISK = N'D:\AdventureWorksEncryptedBackup.bak'
WITH
COMPRESSION,
ENCRYPTION
(
ALGORITHM = AES_256,
SERVER CERTIFICATE = DBBackupEncryptionCertificate
)
GO

Part3 will soon be posted