BATCO

BATCO, short for Battle Code, is a hand-held, paper-based encryption system used at a low, front line (platoon, troop and section) level in the British Army. It was introduced along with the Clansman combat net radio in the early 1980s and was largely obsolete by 2010 due to the wide deployment of the secure Bowman radios. BATCO consists of a code, contained on a set of vocabulary cards, and cipher sheets for superencryption of the numeric code words. The cipher sheets, which are typically changed daily, also include an authentication table and a radio call sign protection system.

BATCO is similar to older Slidex system. The use of BATCO is still taught to Royal Signals Communication Systems Operators as a back-up should secure equipment fail or be unavailable. It is also taught to Army Cadets and Combined Cadets as part of the Signal Classification qualification. BATCO documents are classified as "Restricted" information.