Editing NSA encryption systems (section)

=== Record traffic encryption ===

During [[World War II]], written messages (known as '''record traffic''') were encrypted off line on special, and highly secret, [[rotor machine]]s and then transmitted in five-letter code groups using [[Morse code]] or [[Teletype Corporation|teletypewriter]] circuits, to be decrypted off-line by similar cipher devices at the other end. The [[SIGABA]] rotor machine, developed during this era continued to be used until the mid-1950s, when it was replaced by the [[KL-7]], which had more rotors.

The [[KW-26]] ROMULUS was a second generation cipher device in wide use that could be inserted into teletypewriter circuits so traffic was encrypted and decrypted automatically. It used electronic [[linear-feedback shift register|shift registers]] instead of rotors and became very popular (for a COMSEC device of its era), with over 14,000 units produced. It was replaced in the 1980s by the more compact [[KG-84]], which in turn was superseded by the KG-84-interoperable [[KIV-7]].