What backup encryption methods exist and how to manage encryption keys?

Protecting the confidentiality of backups is a critical security requirement, as backups often contain complete database dumps, user accounts, and trade secrets. If an attacker gains access to the backup storage, the lack of encryption will lead to the instant compromise of all corporate information.

Modern backup systems support encrypting data directly on the source device before sending it to the cloud or an external server. This guarantees information security even in the event of traffic interception or hacking of the storage itself, since exclusively encrypted data is sent to the cloud.

The most common standard is symmetric encryption using reliable cryptographic algorithms. The encryption key is generated individually for each task or the entire storage as a whole, and access to it is protected by a master password or hardware security tokens.

The main difficulty in encrypting backups is managing access keys. The loss of the master key or encryption password guarantees that all backups become completely useless, as it is mathematically impossible to restore encrypted data without it under any conditions.

To solve this problem, corporate environments use external key managers and secure secret storage systems. Keys are separated from the backups themselves and stored on isolated servers or hardware security modules, which only authorized employees of the company's information security department have access to.