KRITIS is a German and European shorthand for critical infrastructure: essential services such as energy, water, transport, telecommunications, and healthcare. These systems are important because their disruption can quickly affect public safety, the economy, and daily life.
In cyber security, KRITIS matters because attackers often target the systems that operators cannot easily take offline. Ransomware, destructive malware, supply-chain compromise, and intrusions into operational technology can interrupt service even when no customer data is stolen. Defenders therefore focus on segmentation, strict access control, monitoring, backup and recovery, and incident response planning. In practice, KRITIS security is about resilience: keeping essential services running, limiting blast radius, and restoring operations fast if an attack succeeds.