Australian Spy Museum takes delivery of rare secret code devices


20th Jan 2026

We’ve had some luck recently with new additions to the Cryptography category – including this ultra-rare 1950’s teleprinter cipher system.

The completed system has two components – a combination of:
– A Swiss Hagelin T-55 teleprinter cipher machine – that is plugged inline between a comms circuit and a teleprinter machine
– A German Siemens T68D teleprinter – used both to compose and send, and also to receive and print – to communicate text over long distance.

When a pair of these is at either end of a link it creates a highly secure point-to-point communications system. In WWII the Germans led in teleprinter-specific cipher machines with the purpose-built SZ-42 (Tunny) and T-52 (Sturgeon), and these were studied in depth by the allies.

Above – Siemens T68D teleprinter


With a relatively compact and rounded Bakelite and metal case this Siemens teleprinter is a gorgeous example of mid-century engineering. It can both read and transmit message tapes and (also can punch & print decrypted messages simultaneously). Below the keyboard is a pull-out tray that stores the machines tape reels.

There was a tan-coloured version for civilians – ours is the military black version that you can also see on display at Bletchley Park.

Above – The Hagelin T-55 cipher attachment

This rare cipher machine features Hagelin’s pin-and-lug cipher mechanism but also a tape reader to input key material from a One Time tape. The machine mixes the content of the tape into the cipher text using the Vernam XOR principle. The resulting super-enciphered text is unbreakable provided the key tape is truly random, and only used once.

The T55’s grey hammertone paint and incredible weight make it resemble Soviet cipher machines more than other Western units.

Above – the internals of the Hagelin T-55 cipher machine

With the T-55’s lid removed you can see how incredibly intricate these machines are from an engineering standpoint.

Front-centre – is the famous Hagelin “pin and lug” cipher mechanism that was originally developed for Hagelin’s standalone mechanical cipher machines. Of note – the set of rotors that came with this machine are mixed alpha-numeric rotors, quite different to those in our other Hagelin machines.
Centre – is the One Time Tape reader
Rear right – is the power supply and
Front-right – is a relay bank that temporarily holds the result for each character to be printed out on tape.

It is great to be able to reunite these rare machines, building out our timeline of how cryptography evolved from the 19th Century into the Digital Age.