Cipher Machines: A Very Real History of Spy Equipment
People might think that rotor machine technology is a relic of the Enigma device, but the HX-63 proved that even later spy equipment had a use for rotors. The Swiss firm Crypto AG was behind the design of the machine, and it was first developed in 1952. Nine rotors were installed in the device, and each rotor had 41 individual contacts. A set of 26 input and output modules connected to the keyboard allowed 15 wires to interface with the rotors via a loop-back connection. Each individual rotor wire could be moved from one of two paths. Rotor movements was entirely irregular, and controlled by switches. Moreover, two plug boards were installed on the device. One was set up to interface with the loop-back module while the other scrambled the input. Nevertheless, there were only ever twelve HX-63 units constructed, and these went to a single agency in the French government.
There is actually still occasionally some development in the field of rotor machine cryptology. A Dutch individual by the name of Tatjana J. van Vark assembled a device in 2002 that was based on the Enigma. However, it used 40-point rotors that had 509 parts each. The TSEC/KL-7, in the world of professional cipher spy equipment, was used as late as 1983 in Canada. It was also occasionally referred to as the ADONIS or POLLUX device, which were code names for the machine.
This particular piece of spy equipment was notable for a strange incident in 1967. John Anthony Walker was once a Chief Warrant Officer in the United States Navy. He walked into the USSR’s embassy in Washington DC, carrying a key list for a version of the machine. Having requested employment as a spy, he eventually issued a guilty plea to charges in a plea arrangement in 1985.
Interestingly enough, the NATO KL-7 device wasn’t necessarily unique. There was a piece of British spy equipment called the BID/60 Singlet, which apparently used 10 rotors. The British adopted it sometime around 1949, and it bares some resemblance to the abovementioned KL-7 design. BID stands for British Interdepartmental, and the BID/60 shares that name with the BID 150. However, the BID 150 is a far different piece of spy equipment.
Instead of relying on individual ciphers, it was a voice encryption system. It was generally used with the Larkspur tactical radio system. Since the US Army had been experimenting with VHF radio communications during the Second World War, the Larkspur system moved forward battle area short-range radio communications from HF AM transmissions to VHF FM. Whenever VHF wasn’t practical, narrow band phase modulation over HF was apparently employed.
The BID 150 was a single channel device, and essentially digitized speech and encrypted it with a digital key. Naturally, a system like this needed very good radio performance, and good radio performance to maintain a digital connection does not come cheap. Vehicles that used the system had to be issued an elevated antenna on a 27-foot mast. A so-called Goodman Box was used to examine signal strength.
While Enigma and the rotor machines might be the most famous devices of the Second World War, the Germans had another piece of spy equipment that was quite amazing. The Schlüsselfernschreibmaschine, Geheimfernschreiber or Siemens and Halske T52 was a type of teleprinter machine that worked from an online point of view. Naval and Luftwaffe units employed the machine, since they could support the heavy device and all the trimmings that came with it.
When Germany occupied Norway and Denmark, they started to use a teleprinter circuit through Sweden to facilitate communications. However, the Swedes quickly tapped the line and Arne Beurling cracked the earliest versions of the machine without much trouble in May 1940. Once the key settings could be found through breaking the code by hand, a similar device manufactured by Ericsson could read incoming messages. While Sweden intercepted around 500,000 messages, the Germans eventually became very much aware of the situation. While Swedish authorities cracked the T52′s advanced models in 1942, the newer upgrades that came in 1943 promised complete security.
Sweden wasn’t the only nation that was hacking German codes, however. The United Kingdom obviously had a keen interest in German spy equipment, and British intelligence codenamed the link between Sicily and Libya Sturgeon. Likewise, forces in the Aegean communicated with those in Sicily over a line codenamed Mackerel. However, the British did not break into Sturgeon as much as they had broken into Tunny or Enigma. On one hand, this was because the Luftwaffe often retransmitted Sturgeon messages using older codes that were easier to break, and thus direct attacks weren’t economical. The other reason, though, had to do with the fact that the T52 used an extremely complicated cipher for its time.
