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Latest Cipher Challenge News


Cipher Challenge Winner Award Prize

Joachim Schueth, from Bonn, won the National Museum of Computing's Cipher Challenge on November 15 last year. Today (Saturday, Jan 26) he received his winner’s prize which included a valve from the working Colossus at the Museum, in Block H at Bletchley Park in Buckinghamshire, the war-time home of Colossus. Using his laptop, Mr Schueth unravelled a code transmitted from the Heinz Nixdorf Museum in Paderborn, Germany, from a Lorenz SZ42 Cipher machine, used by the German High Command to relay secret messages during the war.

Joachim Schueth, speaking in front of Colossus at Bletchley Park, said: “It was unfair because I was using a modern PC, while Colossus was created more than 60 years ago. It really is astonishing and humbling that the world’s first programmable, digital computer was created in the 1940s. Without those Bletchley Park pioneers, I would be out of a job.”


Colossus, the Second World War computer, today successfully deciphered a coded message transmitted from Germany, recapturing the drama and excitement of Bletchley Park's code-breaking legacy.

But, more than 60 years on from when it helped secure the Allied victory in the war, today's Colossus team had to doff their caps to an amateur enthusiast from Germany. Joachim Scheuth, a computer enthusiast from Bonn, was first to crack the message using a program he wrote specifically for the National Museum of Computing Cipher Challenge.

Andy Clark, a director of the National Museum of Computing said: "Colossus has managed to crack the Germans' code just like the old days -- although thankfully today's message was entirely peaceful in content. Mr Scheuth has done fantastically well to decipher the messages first. We are delighted and most impressed by his work."

The Cipher Challenge began yesterday when encrypted messages were transmitted from the Heinz Nixdorf Museum in Paderborn after being encrypted using the Lorenz SZ42 cipher, the same machine used by the German high command in war time.

Meanwhile at Bletchley Park Block H, the computer nerve centre used by Churchill's intelligence operations during the war, a Colossus Mark II machine, which took 14 years to rebuild, clicked and whirred into action. Adverse atmospheric conditions produced by the sun spot cycle interfered with Bletchley Park's reception of the Paderborn transmissions on Thursday.

"While Mr Scheuth was working his way to success, the Colossus team at Bletchley was struggling to get a signal - reminiscent of certain modern-day mobile phone networks," said Mr Clark.

Verifiable cipher text was eventually obtained on Thursday evening and transferred to punched paper tape for Colossus. That text was loaded on Colossus at 0855 today (Fri) and the machine started. By 1315 it had cracked the hardest of the cipher challenge messages, which had content relating to the Heinz Nixdorf Museum in Paderborn. Andy Clark said: "The official run time for Colossus cracking the code was three hours and 35 minutes - we had 45 minutes 'injury time' when we had to replace a valve!" The Cipher Challenge continued tonight for many amateur code breakers still battling to unravel the messages.

The 10 original Colossus machines, which were located at Bletchley Park, enabled code breakers to decrypt top-secret communications sent by German high command, leading to the war being shortened by many months and saving thousands of lives.

"On the strength of today's performance, Colossus is as good as it was six decades ago," said Tony Sale. "We are delighted to have produced a fitting tribute to the people who worked at Bletchley Park and whose brainpower devised these fantastic machines which broke these ciphers and shortened the war by many months."

"The rebuild was extremely difficult because a lack of information, but the actual construction and its operation today was a much easier task. Everything went smoothly until a thyratron valve blew at a very inopportune moment and delayed us by just over half an hour."

Andy Clark concluded: "We are full of admiration for Mr Scheuth's achievement and look forward to inviting him to visit Colossus to receive a very special prize. He wrote a program that was highly optimized for the challenge and he obviously designed it very well. We're really pleased and very impressed. It highlights the strength of the international community working together. I said if someone could crack the code before Colossus I would buy them a beer, so, as a man of my word, Mr Scheuth, the first round's on me!"

15.11.2007   It's been a hectic day at Bletchley Park - the early transmissions from Paderborn were very hard to copy successfully. We appear to be at a particularly difficult point in the sun spot cycle that makes radio transmission between Germany and the UK difficult. Fortunately things improved during the day and we have received better signals at Bletchley Park as the day has progressed. We have had significant help from the Milton Keynes Amateur Radio Society (MKARS) whose receivers and computer based decoders have the edge over our WWII vintage receivers. After some problems with the early transmissions in SZ42 tri-tone mode we have fallen back to standard RTTY transmission to improve the chances of getting good reception of the ciphertext. All transmissions on 16 November will be in RTTY format at 50 baud. We have been inundated with media interest at TNMOC today and have been really pleased to welcome a colleague from the Heinz Nixdorf Museum who has been taking a substantial amount of video footage so that we can document the challenge for posterity. By the end of play on Thursday we have only one good ciphertext to load on to Colossus but hope to validate two others by tomorrow morning. We shall publish the full ciphertexts transmitted by HNF tomorrow on our web site so that those that don't have access to radio receivers can take part in the challenge.

We were concerned to hear that when the SZ42 was turned on this morning in Germany, its main transformer developed a fault and the machine malfunctioned. Fortunately, the team at HNF was able to effect a repair and the cipher machine is back in service. We will be careful not to overuse the SZ42 during the challenge.

HNF has informed us that they hope to have live video on the web so that participants in the challenge can see the activity live in Germany. The web link will be posted in our links section when it is available.

13.11.2007   At a test at Bletchley Park this evening, the original AR88 receivers in the Y Station were having trouble maintaining sufficient frequency stability to copy the ciphertext with the SZ42 encoding scheme for the full duration of the ciphertext transmission. We are unsure if the situation will improve on the higher frequency bands during the daytime transmission schedules. The original transmission format was AM at a much higher power than we are able to transmit for this event. We are using only 100w transmission power with SSB modulation. If we are unable to stabilise the AR88's we will fall back to using a commercial receiver to resolve the signals. If the SZ42 transmission mode proves troublesome with fading problems we will fall back to standard RTTY.
12.11.2007   HNF has received a letter from the Bundesnetzagentur giving them permission to send ciphertext on the frequency bands we plan to use for the transmissions on 15 and 16 November. Although the SZ42 is safely installed in Paderborn at the HNF and has been operating successfully it is 60 years old and we don't want to exhaust it! We want to be sure that we get fully repeatable output for each of our transmissions and so don't plan to use the SZ42 for all the transmissions (it would have to run continuously for nearly 20 hours). We have taken the precaution of punching each of the ciphertext challenges on to paper tape and will use a paper tape reader connected into the tone generators and then the transmitter to guarantee we send the correct ciphertext for each challenge.
05.11.2007   The SZ42 is fully commissioned in Paderborn and working successfully.
01.11.2007   The SZ42 cipher machine and all peripheral components have arrived safely in Paderborn.
08.10.2007   Early tests of the radio path between Paderborn and Bletchley Park have proved successful with RTTY transmissions being sent and received between both stations. Early frequencies have been identified as likely candidates for the real transmissions. We have not tried the SZ42 modulation scheme yet.



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