Editing NSA encryption systems (section)

=== Fleet broadcast ===

US Navy ships traditionally avoid using their radios to prevent adversaries from locating them by [[direction finding]]. The Navy also needs to maintain traffic security, so it has radio stations constantly broadcasting a stream of coded messages. During and after World War II, Navy ships copied these ''fleet broadcasts'' and used specialized ''[[call sign]] encryption'' devices to figure out which messages were intended for them. The messages would then be decoded off line using [[SIGABA]] or [[KL-7]] equipment.

The second generation [[KW-37]] automated monitoring of the fleet broadcast by connecting in line between the radio receiver and a [[teleprinter]]. It, in turn, was replaced by the more compact and reliable third generation [[KW-46]].