--1 创建密钥
create master key encryption by password = '密钥'
--创建证书
create CERTIFICATE BackupCertificate_my
with subject=N'sparksoft certificate'
--3 备份 证书和密钥文件
BACKUP CERTIFICATE BackupCertificate_my TO FILE = 'E:\BackupCertificate_my.cer'
WITH PRIVATE KEY ( FILE = 'E:\BackupCertificate_my.pkey', ENCRYPTION BY PASSWORD = '密钥' );
https://www.abackup.com/enterprise-backup/sql-server-backup-encryption-1016.html