SQL 自2008（还是2005）之后，推出加密功能，可以一定程度上保护数据库的备份安全。
以下测试环境为：sql server 2014
主要目的：将备份的文件加密，在其它电脑上恢复时必须有证书和密钥才可恢复

--1 创建证书

create CERTIFICATE BackupCertificate2

with subject=N'Test certificate'

-- 创建密钥

create master key encryption by password = 'AA@123'

--2 备份主密钥

backup master key

to file=N'g:\db\testbas.cer'

encryption by password=N'AAA@123'

--3 备份 证书和密钥文件

backup CERTIFICATE BackupCertificate2

to file=N'G:\DB\BackupCertificate2.cert'

with private key

(

  file=N'g:\db\master_key2.cer',

  encryption by password=N'AAA@123'

  )

--4、从备份文件中创建证书和密钥

create certificate BackupCertificate

from file =N'c:\sql\BackupCertificate2.cert'

with private key

(

file=N'C:\SQL\master_key2.cer',

decryption by password=N'AAA@123',

encryption by password=N'AAA@123'

)