Define "data breach."

A data breach is defined as an incident where unauthorized individuals gain access to confidential data. This can include sensitive information such as personal identification details, financial records, or any proprietary data that is not meant to be disclosed to the public or unauthorized parties. The key aspect of a data breach is the unauthorized nature of the access, which can result from various factors such as hacking, insider threats, or a failure to secure data adequately.

In contrast, the other options do not accurately describe a data breach. Service interruptions may occur for various reasons, such as technical failures or planned maintenance, but they do not inherently indicate that an unauthorized access event has taken place. A routine security audit is a proactive measure aimed at assessing and improving security controls, not an indication that a breach has occurred. Similarly, methods for securing sensitive information refer to preventive measures rather than incidents of unauthorized access. Therefore, the definition of a data breach focuses specifically on the unauthorized access aspect, making the second choice the most accurate.