Federated architecture is a distributed design in which independent nodes keep control of their own data, systems, or policies while exposing governed interfaces for approved reuse. Instead of copying everything into one central repository, each participant publishes only what others are allowed to query or consume. This is common in public-sector platforms, data spaces, and multi-organization services where trust, ownership, and legal constraints matter.
In cyber security, federation changes the trust boundary. It can reduce data sprawl and limit the blast radius of a compromise because sensitive records remain local. But it also creates new risks: attackers may target the weakest node, abuse shared APIs, spoof service identities, or exploit poor authorization and logging. Defenders need strong identity controls, access policy enforcement, versioning, provenance tracking, and monitoring across every node. A secure federated architecture makes reuse possible without surrendering control.