Which of the following is NOT a requirement of PCI DSS for organizations?

The requirement that is not a part of PCI DSS is related to the mastery of all security technologies. PCI DSS focuses on establishing a comprehensive security framework to protect cardholder data rather than requiring an organization to have in-depth expertise in every available security technology. Organizations are encouraged to adopt best practices, implement various security measures, and ensure compliance with the standards, but they are not mandated to master every technology involved in the security landscape.

In contrast, the other options represent critical components of the PCI DSS requirements. Regular vulnerability assessments are necessary to identify and mitigate security weaknesses, maintaining a secure network is essential for protecting cardholder data, and implementing strong access control measures helps ensure that only authorized personnel have access to sensitive information. Each of these aspects is fundamental to achieving compliance with PCI DSS, focusing on practical security measures rather than a complete mastery of all security-related technologies.