What technology is often used to ensure the privacy of data at rest?

Data masking is a technology designed to protect sensitive information by obscuring specific data within a database. This approach is particularly valuable for ensuring the privacy of data at rest, as it replaces original data with a modified version that cannot be readily understood or used by unauthorized individuals. By using techniques such as character substitution, data masking allows organizations to use data for testing, training, or analytical purposes without exposing sensitive information, thus safeguarding the privacy of individuals and organizations.

In contrast, other technologies listed do not primarily focus on the privacy of data at rest. Biometric scanners are essential for authenticating users accessing systems, but they do not directly concern data privacy once the data has been stored. Firewalls serve as perimeter defense mechanisms, controlling incoming and outgoing network traffic, which helps protect data in transit rather than at rest. Secure file transfer protocols facilitate the safe transmission of data between systems but do not address the encryption or modification of data sitting idle in storage. Therefore, data masking stands out as the correct choice for ensuring the privacy of data that is not actively being processed or transferred.