In the lesson's CIA examples, shutting down a system is an attack on ______ because authorized users can no longer access it.

### Why this is right Availability is the goal that concerns timely and uninterrupted access for authorized users. Shutting down a system prevents those users from accessing its resources, so it is an availability impact. ### The concept The CIA model separates three kinds of protection. Confidentiality asks whether information is kept from unauthorized viewers. Integrity asks whether information stays accurate and unaltered. Availability asks whether authorized users can reach the systems and information they need. A shutdown can be deliberate or accidental; the security impact is the loss of access either way. The lesson uses a shutdown command on a lab virtual machine as a simple demonstration, not as permission to disrupt a real service. A defender responding to an availability incident would focus on restoring access and understanding why the service stopped. By contrast, restoring a file's correct contents addresses an integrity problem, while restricting access to exposed information addresses a confidentiality problem. ### Watch out A system shutdown might also affect the integrity of work in progress, but the direct and intended classification in this example is availability because users cannot use the system. ### Terms - **CIA**: Confidentiality, Integrity, and Availability, the information-security goals in the lesson. - **Availability**: Timely access to information and resources for authorized users. - **Integrity**: The protection of data from unauthorized alteration. - **Confidentiality**: The protection of sensitive information from unauthorized access or disclosure. - **Virtual machine**: A software-based computer used to run an isolated lab system. ### Remember When the central consequence is that users cannot use a resource, classify it as an availability impact.