nøkkelhierarki

A key hierarchy, often referred to as a key management hierarchy or certificate hierarchy, is a structured system for organizing and managing cryptographic keys. In this structure, keys are arranged in a tree-like fashion, with a root key at the top. This root key is typically a master key, responsible for encrypting or signing other keys.

Each level in the hierarchy contains keys that are derived from or protected by the key at the level above it. For example, a top-level key might encrypt intermediate keys, which in turn encrypt data encryption keys. This allows for a tiered approach to security. If a key at a lower level is compromised, the impact is limited to the data it protects, rather than the entire system.

The primary benefit of a key hierarchy is enhanced security and manageability. By distributing trust and responsibility across different levels, it becomes easier to revoke access or replace compromised keys without affecting the entire key infrastructure. It also facilitates the delegation of authority, where different entities can be entrusted with managing keys at specific levels.

Key hierarchies are commonly employed in various security applications, including Public Key Infrastructure (PKI) systems, where a root Certificate Authority (CA) issues certificates to intermediate CAs, which then issue certificates to end-entity users or devices. This layered approach ensures the integrity and authenticity of digital communications and transactions. The strength of the hierarchy relies heavily on the security of the root key; compromising the root key would compromise the entire hierarchy.