Which security principle focuses on ensuring that data is accessible when needed?

The security principle that focuses on ensuring that data is accessible when needed is availability. This principle is a fundamental aspect of the CIA triad, which stands for Confidentiality, Integrity, and Availability. Availability ensures that information and resources are accessible to authorized users when required, and it emphasizes the importance of having systems and data in a usable state.

In practice, this means implementing measures such as redundancy, failover systems, backups, and proper maintenance to reduce downtime or data loss. Constraints on availability can arise from various factors including hardware failures, natural disasters, cyberattacks, or misconfigured systems, all of which need to be managed effectively to maintain the continuous availability of services and information.

Understanding availability is crucial for organizations to ensure that their operations can carry on effectively without interruptions, which would otherwise disrupt business processes and lead to financial losses or damage to reputation.