An encrypted system backup is a copy of system data, configurations, or secrets that is protected with cryptography before it is stored or moved. If someone steals the backup file, encryption makes the contents much harder to read without the key. This matters because backups often contain high-value material such as password hashes, admin credentials, keys, or recovery settings.
In cyber security, backup encryption reduces the impact of device theft, cloud exposure, insider access, and misconfigured storage. Attackers often target backups because they can be easier to obtain than a live production system. If a backup is not encrypted, a single exposed file can turn into credential theft, lateral movement, or data disclosure. Strong backup encryption should be paired with tight access control, key management, and regular restore testing, because encryption protects confidentiality but does not by itself guarantee availability or integrity.