Introduction
Transparent Data Encryption (TDE) in SQL Server secures sensitive data by encrypting database files at rest without impacting application access, helping organizations protect against unauthorized data exposure.
Steps to Configure TDE:
- Create a Database Master Key (DMK):
This key is created in the master database and secured with a password. It protects the certificates and asymmetric keys used in encryption.
USE master;
CREATE MASTER KEY ENCRYPTION BY PASSWORD = ‘StrongPasswordHere!’;
- Create or Obtain a Certificate:
Create a certificate in the master database protected by the DMK. This certificate will encrypt the Database Encryption Key (DEK).
CREATE CERTIFICATE TDECert WITH SUBJECT = ‘TDE Certificate’;
- Create a Database Encryption Key (DEK):
Switch to the user database to be encrypted, then create the DEK encrypted by the certificate. SQL Server supports AES (128, 192, 256) or Triple DES algorithms.
USE YourDatabase;
CREATE DATABASE ENCRYPTION KEY
WITH ALGORITHM = AES_256
ENCRYPTION BY SERVER CERTIFICATE TDECert;
- Enable Encryption on the Database:
Set the database encryption on to start encrypting the database files (data and log).
ALTER DATABASE YourDatabase SET ENCRYPTION ON;
- Backup the Certificate and Private Key Securely:
Immediately back up the certificate and the private key to a secure offline location, because without these you cannot restore or attach the encrypted database.
BACKUP CERTIFICATE TDECert
TO FILE = ‘C:\Backup\TDECert.cer’
WITH PRIVATE KEY (FILE = ‘C:\Backup\TDECert_PrivateKey.pvk’,
ENCRYPTION BY PASSWORD = ‘AnotherStrongPassword!’);
Conclusion:
By properly configuring and managing TDE with strong security practices, you can safeguard your database, ensure compliance, and maintain readiness for data recovery in the event of security incidents.
