The World War II computer Colossus has successfully deciphered a coded message transmitted from Germany, recapturing the drama and excitement of Bletchley Park's code-breaking legacy – but it wasn't the first to crack the code. That honour went to a German computer enthusiast using a program he wrote himself. 

Experts using the newly-rebuilt machine at the National Museum of Computing in Bletchley Park in the US managed to beat a number of rival code breakers using modern-day computers. But 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, comments: "Colossus has managed to crack the Germans' code just like the old days – although thankfully today's message was entirely peaceful in content. Scheuth has done fantastically well to decipher the messages first. We are delighted and most impressed by his work."
The Cipher Challenge began with encrypted messages 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.
However, adverse atmospheric conditions produced by the sun spot cycle interfered with Bletchley Park's reception of the Paderborn transmissions on Thursday.
"While 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," says 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 08h55 on Friday morning and the machine started.  By 13h15 it had cracked the hardest of the cipher challenge messages, which had content relating to the Heinz Nixdorf Museum in Paderborn.
Clark says: "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."