The Homeland Security Information Network (HSIN) (previously the Homeland Security Data Network (HSDN)) is a secure, web-based system of integrated communication networks designed to facilitate information sharing between the U.S. Department of Homeland Security (DHS) and other federal, State, county, local, tribal, and private sector commercial and other nongovernmental organizations involved in identifying and preventing terrorism, as well as in undertaking incident management activities.
HSIN facilitates real-time information sharing at the sensitive but unclassified level. The network is composed of more than 35 community-of-interest topic-portals, such as Intelligence, Law Enforcement, and Emergency Management.
It is the collaborative system used by the DHS Operations Center to collect and disseminate information between DHS and local, state, tribal, and federal agencies involved in combating terrorism. HSIN also includes public safety and private sector connectivity (USP3), homeland security, and other information.