What is the primary purpose of intrusion-detection and intrusion-prevention systems in PCI DSS guidance?

• A. Detect and/or prevent intrusions into the network.
• B. Encrypt data in transit.
• C. Manage user access controls.
• D. Store audit logs.

Answer: (A)

The main idea is that intrusion-detection and intrusion-prevention systems are about watching network traffic to find and stop unauthorized activity. An IDS continuously analyzes data for suspicious patterns and raises alerts so security teams can respond. An IPS goes further by actively blocking or stopping harmful traffic in real time, reducing the chance of a breach. This is why their primary purpose in PCI DSS guidance is to detect and/or prevent intrusions into the network. The other options describe encryption, access control, or logs, which are important security measures but are not the primary function of IDS/IPS.