Colossus beaten

A German radio amateur appears to have beaten the reconstructed Colossus Mark II, thereby winning the Cipher Event. Bonn resident Joachim Schüth (call-sign: DL2KCD) managed to stabilise and read the very noisy radio transmission of the Cipher text at 12:00 UTC and decipher it by 14:00.

The Cipher challenge was started at 9:00 yesterday (Thursday) morning. Radio amateurs and cryptologists were invited to decipher radio messages generated by a Lorenz SZ42 teleprinter and transmitted using the original radio protocol. The code breakers are challenging a reconstruction of the computer which decoded the radio messages of the German World War II High Command 63 years ago. The event celebrates the successful rebuild of Colossus Mark II at the British National Museum of Computing and Cryptography at Bletchley Park. Constructed by Alan Turing, the computer played a major role in deciphering German messages during World War II. However, British and German secret services initially had reservations about the cipher challenge.

To decipher the code, Schüth used a program he wrote in the ADA programming language and has since published with comments on his web site. His 1.4 GHz PC needed 46 seconds to decipher the message. Meanwhile, the Colossus Mark II rebuild started computing this morning at 7:30, as in England the first usable radio signal could only be recorded at 16:30 yesterday afternoon.

(Detlef Borchers)

(mba)