This was a time sensitive, voice authentication system which used a one time PAD. It was used in the 1970s by the BAOR (British Army of the Rhine) . The system came into use around 1967 but only lasted a few years. It was rendered redundant once the BID150 speech encryptor was introduced into service. Triton itself wass rushed into production perhaps to meet somenew threat.
The main purpose of the device was to provide a secure means of authenticating a voice radio station on the most important voice radio nets. Prior to its introduction, BAOR used a very simple authentication system - the comms plan carried a matrix of letters and a challenge comprised "Callsign 23, I challenge KILO VICTOR." The other station would look up the row/column to find the reply:
"Callsign 0, I respond FOXTROT YANKEE."
The main fault with his system was that an enemy station could be challenged, quickly change nets, use the challenge to learn the correct reply; then return to the original net and give the correct pair of letters! TRITON was a thick small book for one-time use. Amazingly, the challenge/response was based on the DAY NUMBER and TIME - the time was in very short chunks so the correct response had to be given within the same 'chunk' - a minute or so.
The entire Triton system was awkward to use. It took some time to find the correct book, page number and the time. Then a small plastic cursor was to get the correct response. It is not known if Triton ever stopped the Warsaw Pact SIGINT from ever joining British nets but it certainly stopped BOAR communications far too much.