SQL Server › Transparent Data Encryption

Why is it critically important to back up the certificate used for Transparent Data Encryption, and what happens if it is lost?

Intermediate

Answer

If the certificate used to protect a TDE encrypted database is lost without a proper backup, you will be permanently unable to restore that database's backups or attach its data files on a different server, since the certificate is required to decrypt the database encryption key, making a certificate backup just as important as the actual database backups themselves.

BACKUP CERTIFICATE MyServerCert
TO FILE = 'C:\Backups\MyServerCert.cer'
WITH PRIVATE KEY (
  FILE = 'C:\Backups\MyServerCert.pvk',
  ENCRYPTION BY PASSWORD = 'StrongPassword123!'
);

Real-world example A company that enabled TDE without properly backing up their certificate discovers, after a hardware failure, that their database backups are completely unusable, learning a costly lesson about the absolute necessity of also backing up TDE certificates.

Common follow-ups: Where should the certificate backup be stored for maximum safety?;How do you restore a TDE encrypted database onto a completely different server?

Backup & Recovery;SQL Server Security & Permissions