Which type of encryption protects data at rest?

Which type of encryption protects data at rest?

• A. Encryption in transit
• B. Data compression
• C. Encryption at rest
• D. Firewall

Answer: (C)

Protecting data when it’s stored on disks or backups is achieved with encryption at rest. Data at rest means information that is stored on devices, databases, or storage media and isn’t actively moving over a network. Encrypting this stored data makes it unreadable to anyone who gains access to the storage medium without the proper decryption keys. This protection is provided by approaches like full-disk encryption or file- or database-level encryption, which guard you against physical theft or unauthorized access to the storage itself. In contrast, encryption in transit protects data as it travels over networks, preventing eavesdropping while it’s being transmitted. Data compression is a method to reduce file size, not a security measure. A firewall is a security device that controls traffic, not an encryption method. So, the mechanism that protects data while it’s stored is encryption at rest.

Protecting data when it’s stored on disks or backups is achieved with encryption at rest. Data at rest means information that is stored on devices, databases, or storage media and isn’t actively moving over a network. Encrypting this stored data makes it unreadable to anyone who gains access to the storage medium without the proper decryption keys. This protection is provided by approaches like full-disk encryption or file- or database-level encryption, which guard you against physical theft or unauthorized access to the storage itself.

In contrast, encryption in transit protects data as it travels over networks, preventing eavesdropping while it’s being transmitted. Data compression is a method to reduce file size, not a security measure. A firewall is a security device that controls traffic, not an encryption method.

So, the mechanism that protects data while it’s stored is encryption at rest.