Federated data is data that remains under the control of the organization that created or stores it, while other organizations can query, analyze, or collaborate on it through agreed rules. Instead of copying sensitive records into one central repository, each participant keeps local storage, local access controls, and local governance.
In cyber security, this model matters because centralizing data can increase the blast radius of a breach. Federated designs can reduce exposure of health records, research data, or operational logs by limiting movement and sharing only the minimum necessary information. They also create new security requirements: strong identity management, granular authorization, encryption in transit, audit logging, and trusted provenance so partners can verify what was accessed and changed. Attackers may try to abuse trust between organizations, steal federation tokens, or poison shared datasets. Defenders use segmentation, short-lived credentials, and strict policy enforcement to keep collaboration useful without giving up control.