One should not be surprised by the astounding variety of odd things that are advertised on eBay – it has often proved to be a very lucrative site for those selling, those buying and even for those ‘just looking’. Not long ago, a ‘serendipity’ moment occurred when a volunteer museum worker, while scanning the eBay site, came upon a photograph of what seemed to be an antiquated teleprinter. It turned out to be exactly that – only this one was part of a Lorenz encryption machine used by Hitler and his High Command during WWII!
Today, at Bletchley Park, the site of ultra-secret work in coding and decoding during WWII, there stands The National Museum of Computing which houses all sorts of exciting and interesting WWII encryption, computer and related memorabilia. There are a number of keen volunteers who work there – and it was one of them who came upon the photograph on eBay. On further investigation, the teleprinter was located, abandoned in a shed, but still in its original case. The owner was quite happy to part with this ‘junk’ for the sum of £10 (approximately US$14) and it has now been placed in a secure spot within the museum.
The teleprinter turned out to be part of one of the very few extant Lorenz machines, which were used by the German High Command, as well as by Hitler when communicating with his top Generals. The swapping of secret messages and the sending of classified messages were trusted to the ‘unbreakable’ encoding of these machines. This teleprinter is an exciting ‘find’ and has brought the Museum closer to having a complete, functioning, Lorenz machine. The last component necessary before the full process of encoding a German message can be re-created, is a motor, which the museum hopes will eventually be forthcoming.
During WWII, the German Army utilised a number of different cipher machines, of which the best known one was the Enigma machine. The Siemens T – 53 (Geheimschreiber,) was also a very successful machine, which made use of teleprinters, but for the highest level of secret communications, the Germans used the Lorenz SZ- machines which could be used both off-line and on-line and utilised wireless telegraphy. The SZ represented the word ‘Schlussel-zusatz’ which translates to ‘cipher attachment’ for the Lorenz was an in-line attachment to a standard teleprinter.
The Lorenz system had an electro-mechanical wheel-based cipher, using 12 pinwheels for encryption. Each wheel had a range of pin positions which were changed each day in the interests of greater security. In order for the enciphering and the deciphering to work, both the transmitting and the receiving machines needed to have their pinwheels set identically. The teleprinter allowed messages to be typed in the German language. The message would then be encrypted by the Lorenz cipher machine and transmitted via wireless telegraph which was deemed safer than the usual land lines.
The Lorenz SZ-40, began transmissions in June 1941, and was soon followed by two upgraded versions, the SZ-42a and the SZ-42b. They were relied upon for transmitting the highest-level communications between the German High Command and Army commandoes in occupied Europe, and were found to be highly successful. In spite of the prowess of the Bletchley Park code-breakers, the system may well not have been ‘cracked’ had a particular message, intercepted by one of Britain’s Y-stations, not been incorrectly received. The message was thus sent a second time, although a little carelessly, with sufficient differences to give the British cryptographers at Bletchley the ‘break’ they needed. They immediately set to work on the decoding of these two TUNNY (codename for the Lorenz SZ machines) messages.
Without ever having seen a Lorenz machine, (the first Lorenz was only captured in 1944) the code-breakers managed to envision its structure and set about creating their own machines. It was an amazing feat. The first machine was the remarkable ‘Heath Robinson’ which used two paper tapes which, unfortunately, created problems with regard to keeping them synchronised, which caused results to be slow. It did however, lead the way to the creation of what is seen today as the very first electrical digital computer – the Colossus. It was this extraordinary machine, together with all the other input, that finally cracked the code and enabled the Bletchley Park cryptographers to decipher these top-secret Nazi communications. Being able to read the German high level and most strategic Lorenz messages was of vital importance to the Allies. It resulted in tremendously significant information for British intelligence and greatly contributed to the victory of the Allies in Europe.