What is the primary purpose of network segmentation in compliance with PCI DSS?

The primary purpose of network segmentation in compliance with PCI DSS is to reduce scope and risk. By segmenting the network, organizations can isolate the cardholder data environment (CDE) from other parts of the network. This isolation limits the number of systems that come into contact with sensitive payment data, effectively narrowing down the areas that need to be compliant with PCI DSS requirements.

Additionally, segmentation minimizes the attack surface available to potential intruders, thereby decreasing the overall risk posed to cardholder data. It allows for more targeted security measures and helps streamline compliance efforts since fewer systems are subject to the rigorous controls mandated by PCI DSS.

While enhancing user experience, increasing transaction speeds, and facilitating data sharing are relevant considerations in a network environment, they do not align with the core objectives of PCI DSS in terms of protecting payment data and minimizing compliance scope. The direct focus on security risk and scope reduction through segmentation is what makes it essential for PCI DSS compliance.