PCI DSS 4.0 Compliance Guide: Integral for developers integrating payment systems; security protocols evolved from PCI DSS 3.2.1. Key requirements (6.4.3, 11.6.1) focus on authorization, verification of client-side scripts due to rising attacks. Security must be embedded from development's start to prevent vulnerabilities; managing script dependencies and real-time monitoring is essential for protecting payment data and ensuring compliance.
