Key separation is a security design that splits control over signing material so no single person, system, or component can approve a transfer alone. In practice, one part may hold a signing key, while another part enforces policy, confirms the destination, or adds a second approval step. The goal is to remove any single point of failure for high-value actions.
This matters in cyber security because attackers often target the fastest path to a valid signature. If one stolen credential or one compromised host can authorize withdrawals, funds can move immediately and be hard to recover. With key separation, defenders can require multi-party approval, hardware-backed signing, threshold schemes, or separate operational roles. In real attacks, weak separation shows up when a hot wallet, admin panel, or automation job can sign too much on its own. In defenses, it limits blast radius and helps stop a breach from becoming a full drain.