Explanation
To encrypt a backup we need to configure an encryption algorithm (supported encryption algorithms are: AES
128, AES 192, AES 256, and Triple DES) and an encryptor (a certificate or asymmetric key).
Example: in order to create an encrypted backup we must create a Database Master Key.
USE SampleDB
GO
CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'MSSQLTips.com';
GO
We must create a certificate to act as an encryptor.
Use SampleDB
GO
CREATE CERTIFICATE SampleDB_Backup_Certificate
WITH SUBJECT = 'SQL Server 2014';
GO
Now we are ready to create encrypted backups.
References: https://www.mssqltips.com/sqlservertip/3145/sql-server-2014-backup-encryption/