Cybersecurity in Networks Supporting Card Payment Systems

The article examines cybersecurity in networks supporting card payment systems, which serve as a distributed critical infrastructure characterized by high transaction volumes, dense data concentration, and escalating cyber threats. The study aims to conceptualize the payment card environment not merely as a set of isolated components, but as interdependent domains of trust through which a single transaction simultaneously traverses terminals, gateways, processors, schemes, and issuing and acquiring banks. The relevance is grounded in the structural dominance of card payments in retail and remote commerce, the documented growth of ransomware, data exfiltration, and DDoS campaigns against financial institutions, as well as the tightening regulatory focus on cardholder data protection and operational resilience. The novelty of the work lies in its tri-layered analytical design, which combines the architectural decomposition of the payment chain, a normative–taxonomic reading of PCI DSS concepts related to cardholder data, sensitive authentication data, and controlled environments, and a threat-oriented mapping of prevalent attack classes onto this architecture. This perspective enable