Image: Colossus computer
Tony Sale
In 1994, a team led by Tony Sale began a reconstruction of a Colossus code-breaking machine. Here, in 2006, Sale supervises the breaking of an enciphered message with the completed machine.
updated 11/16/2007 5:32:48 PM ET 2007-11-16T22:32:48

A rebuilt World War II code-cracking computer developed to intercept Nazi messages lost to a desktop computer Friday in a contest to decipher an encrypted radio message.

The challenge marked the first time the Colossus machine had been used since former Prime Minister Winston Churchill ordered models of the top secret computer destroyed, according to Britain's National Museum of Computing, which organized the contest.

Churchill had feared Britain's national security would be threatened if the state of the art computer's technical details ever leaked out.

However, not only was Colossus beaten by a home computer, but by one in Germany.

Bonn-based software engineer Joachim Schueth deciphered the message, which was encrypted by a Nazi-era Lorenz cipher machine and transmitted by radio from Paderborn, Germany. It took him two hours Thursday, using ham radio equipment and a computer program he wrote especially for the challenge.

Schueth paid tribute to Colossus and those who used it during WWII at the Bletchley Park code-breaking center, outside London, saying their work was important to Germans because "it helped to shorten the lifetime of the Nazi dictatorship."

But Colossus, the world's first programable computer, was no match for its electronic descendants, he said.

"Putting Colossus in a competition with modern computers may be a bit unfair," Schueth wrote on his Web site.

Colossus eventually completed the challenge at 1:15 p.m. Friday, taking three hours and 35 minutes, after overcoming difficulties intercepting the distant radio signal and repairing a blown valve.

"We've lost appreciation of just how hard it was to intercept signals, interpret them and put them on Colossus and run them," said Andy Clark, director of the Bletchley Park-based computing museum.

"The past two days have brought into sharp focus just how hard they had to work," he said.

Experts spent 14 years rebuilding the Colossus using stolen design plans and by gleaning information from those who helped create the original.

Ten Mark II Colossus machines enabled code breakers at Bletchley to decipher top-secret communications sent by the Nazi high command, and have been credited with shortening the war by months and saving thousands of lives.

The rebuilt computer will continue to operate as the museum's centerpiece, Clark said.

Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


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