Common Entity Index Prototype (CEI Prototype), September 26, 2013, PDF, 18 pages. DHS’ Office of the Chief Information Officer (OCIO) is developing a new system called the CEI Prototype to enable DHS to correlate and consolidate a limited set of identity data from select component-level systems, and organize key identifiers collected about individual members of the public. The purpose of this prototype is to determine the feasibility of establishing and effectively controlling access to a centralized index of select biographic information, enabling DHS to provide correlated and consolidated identities. This PIA was conducted because it will use datasets provided by select DHS components containing PII for testing and evaluation purposes. If the system passes the testing and evaluation stage and DHS moves to an operational system, a new PIA will be published.