How do denial of service attacks affect system availability?

Denial of Service (DoS) attacks are specifically designed to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of traffic or resource requests. This saturation prevents legitimate users from accessing the system, leading to unavailability. Therefore, the assertion that DoS attacks make the system inaccessible to users captures the essence of how these attacks compromise system availability.

In contrast, options that suggest an increase in system capacity or improvements in response times do not align with the nature of DoS attacks. Those attacks diminish the ability of the system to handle requests, ultimately leading to degraded performance and lack of access. Additionally, encrypting data to protect information points toward an entirely different type of security measure—encryption is aimed at safeguarding data confidentiality rather than directly addressing system availability challenges posed by a Denial of Service attack.