What is an essential requirement for data at rest in terms of confidentiality?

• A. Public availability
• B. Regular audits
• C. Access control
• D. User authentication

Answer: (C)

For data at rest, ensuring confidentiality is primarily focused on controlling who can access the data. Access control acts as a gatekeeper, allowing only authorized individuals or systems to interact with the data stored on devices, servers, or databases. This is crucial since unauthorized access can lead to data breaches, exposing sensitive information. Effective access control mechanisms might include measures such as user roles, permissions, and policies that limit access based on necessity.

While public availability is the opposite of what is required for confidentiality, regular audits are more about ensuring compliance and assessing measures in place rather than directly securing data. User authentication is also important in the overall security infrastructure, but it primarily serves as a method of verifying identity rather than directly managing access permissions. Therefore, access control stands out as the essential requirement specifically for maintaining confidentiality of data at rest.