The Homeland Security Department is adopting a federated database approach to information sharing, according to privacy recommendations presented by the department's Data Privacy and Integrity Advisory Committee.

A federated approach means that rather than consolidating databases into a single, centralized one, users can search multiple databases from a single point. The extent to which a federated approach creates in effect a virtual centralized database depends greatly on its implementation. The advisory committee says it recommends that the search query functionality--what it calls a "hub"--be limited to a display of pointers to participating DHS component databases, an audit log and a knowledge management tool.

The tool would be necessary to resolve a problem that crops up in federated access, the committee says--namely, the necessity of users from outside the component that maintains the database to make a judgment on the quality of the data retrieved through a federated search.

Data, despite its air of finality when displayed on a computer screen, is in fact highly variable in reliability and sometimes accurate or not depending on the context of its use. A knowledge management tool would identify the purpose for which the data was collected, permissible uses, how often it has been updated and other relevant information, the committee says.

As for access control to data via federated search, the committee favors an at least somewhat-centralized approach under which a DHS-wide organization would have responsibility for determining who may have access to particular databases included in the federated search and for what purpose.

DHS currently has a decentralized approach in which the direct owners of databases make determinations of who's allowed to access them. This model undermines the point of a federated approach, since the search results from a federated search may turn up results from databases whose existence is unknown to the user.

"Although potential users likely are aware of databases that are relevant to routine queries, they may be less aware of those that are relevant to an idiosyncratic need for information," the committee says.

For more:
- download the committee's recommendations (.pdf)

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