You will need to backup and restore Notification Server KMS encryption keys for the following reasons.
IT Management Suite (ITMS) 7.6, 8.0, 8.1, 8.5, 8.6
The Notification Server uses the Key Management System (KMS) encryption keys to protect sensitive data. You can take a backup of the Notification Server
KMS encryption keys at any time in the Symantec Installation Manager (SIM).
To back up and restore Notification Server cryptographic keys:
To back up KMS encryption keys:
The Backup Notification Server Cryptographic Keys page appears after the installation
To restore KMS encryption keys:
Source: Backing up and restoring Notification Server KMS encryption keys
Starting with ITMS 8.5 and later, you can Import and Export Encryption Keys using the SMP Console:
Go to Settings>All Settings>Notification Server>Notification Server Settings>Encryption Keys Management>Export
As well, you can also schedule to backup important information like Notification Server Configuration and Software Library files:
Go to Settings>All Settings>Notification Server>Notification Server Settings>Critical Data Backup