Which of the following is a key characteristic of a DDoS attack?

A Distributed Denial-of-Service (DDoS) attack aims to make a network service unavailable by overwhelming it with a flood of traffic from multiple compromised systems. This attack often utilizes a botnet, which is a collection of malware-infected devices, to send an enormous volume of requests to the target server or network, ultimately disrupting normal functioning. DDoS attacks can vary in type, including volume-based attacks, protocol attacks, and application layer attacks, each targeting different aspects of network infrastructure. Option A is incorrect because DDoS does not exploit client-side vulnerabilities but rather aims at overwhelming server resources. Option C is incorrect as data theft is not the goal of a DDoS attack; instead, it seeks to disrupt services. Option D is incorrect because DDoS is a network-level attack, not primarily a physical security concern. Option E is incorrect because breaking encryption involves different attack vectors, not DDoS.