A cross-domain solution (CDS) is an integrated information assurance system composed of specialized software, and sometimes hardware, that provides a controlled interface to manually or automatically enable and/or restrict the access or transfer of information between two or more security domains based on a predetermined security policy. CDSs are designed to enforce domain separation and typically include some form of content filtering, which is used to designate information that is unauthorized for transfer between security domains or levels of classification, such as between different military divisions, intelligence agencies, or other operations which critically depend on the timely sharing of potentially sensitive information.