Identity and authorization are the controls that answer two basic security questions: who is this system, and what is it allowed to do? Identity proves a service, agent, or user is genuine, often through keys, certificates, tokens, or signed messages. Authorization then limits actions based on policy, such as read-only access, scoped API permissions, or per-task roles.
They matter because a trusted system can still be dangerous if its permissions are too broad or if its identity can be spoofed. In cyber attacks, weak identity checks let attackers impersonate services, move laterally, or send malicious commands through trusted channels. In defense, strong identity and authorization support least privilege, message verification, and audit logs, making it harder for compromised agents or accounts to trigger unauthorized actions across a network.