Which of the following is NOT a common type of cyberattack?

The option regarding encryption keys is not classified as a type of cyberattack. Instead, encryption keys are fundamental components of cryptographic systems used to secure data by converting it into an unreadable format that can only be deciphered with the appropriate key. While encryption techniques help protect information, they do not, in themselves, constitute an attack strategy.

In contrast, DDoS attacks, ransomware, and spyware clearly align with malicious cyber activities. DDoS (Distributed Denial of Service) attacks involve overwhelming a target system with traffic to disrupt its normal operations, while ransomware is designed to encrypt a victim’s files and demand a payment for the decryption key. Spyware is a type of malware that secretly gathers user information without consent. All these methods represent intentional efforts to compromise security and exploit vulnerabilities, unlike encryption keys, which serve a protective function in data security.