How do you implement cybersecurity for DCS systems?

DCS cybersecurity implementation per IEC 62443: network segmentation (zones and conduits, firewalls between layers), access control (role-based access, strong authentication, no default passwords), patch management (vendor-tested patches, change control process), endpoint hardening (disable unused services, antivirus where compatible), monitoring (network traffic analysis, log collection, security events), physical security (locked cabinets, controlled access), and backup/recovery (offline backups, tested restore procedures). Defense in depth: multiple security layers, assume breach mentality. Regular security assessments and penetration testing. Train personnel on security awareness. Document security architecture and incident response procedures.