Availability concept

• A. Non-repudiation means digital signatures
• B. Availability means authorized users always have access to resources
• C. Integrity means preventing service outages
• D. Confidentiality means encrypting data at rest

Answer: (B)

Availability is about ensuring authorized users can access resources when they need to. It relies on uptime and reachable services, backed by redundancy, failover, backups, and monitoring so outages are minimized and recoveries are fast. The idea expressed here—authorized users always have access to resources—captures this goal of keeping services usable.

Non-repudiation is about proving who sent or signed something, often with digital signatures, to establish accountability, not about keeping systems accessible. Integrity focuses on data being accurate and unaltered, which is about trustworthiness of information rather than whether a service is available. Confidentiality concerns protecting information from being read by unauthorized parties, such as through encryption, which is about secrecy rather than guaranteeing access to services.