Reason to back up Database master Key?

I can backup this key using something like:

BACKUP MASTER KEY TO FILE = 'c:\TestEncryptionMasterKey.key'

ENCRYPTION BY PASSWORD = '23'

but why would I need to do it as the DBMK is stored in the databases itself ( in sys.symmetric_keys) and we dump all databases nightly. Just "in case"?

TIA,

barkingdog

Yes, we recommend you do this as a recovery measure. If you have a backup of the database anyway, this is less important because the DBMK is also backed up anyway, but this is still good as a precaution. Especially since restoring a DBMK file is a lot less expensive (in terms of server downtime) than restoring a full database backup.

Sung