BOOK REVIEW : Colossus that bestrode an Enigma

The Times
March 11, 2006

Colossus that bestrode an Enigma
--------------------------------
Review by Simon Singh

COLOSSUS
by Paul Gannon
Atlantic, £25; 562pp

EVERYONE IS PROBABLY familiar with the Enigma cipher machine. However, few 
have heard of the Geheim- schreiber ( "the secret writer" ), another 
German cipher machine from the Second World War, much more complex and 
subtle and used to transmit the Third Reich’s deepest secrets.

In his account of the Geheimschreiber and its deciphering by British 
code-breakers at Bletchley Park, Paul Gannon has revealed a previously 
untold story.

Geheimschreiber described a family of cipher machines employed to protect 
the communications of the Nazi High Command. The Allies were desperate to 
crack it but it was a generation ahead of Enigma, not just in terms of 
security but also in efficiency....../snip/

...In tackling the story of Colossus, Gannon weaves together four strands. 
He explains the cryptography in detail, and gives an equally rigorous 
account of how it influenced military strategy. Thirdly, and possibly 
closest to his heart, he argues that Colossus was an historic breakthrough 
in computing. Bletchley's machine was kept secret for a decade, and has 
been overshadowed by rivals, but Gannon sets the record straight.

Finally, Gannon tells of the heroic efforts of the inventors and 
mathematicians. Because Colossus was top secret, they received no 
recognition for decades. As soon as the project closed, Tommy Flowers took 
all his documents to the boiler room and burnt them. He continued in 
telecoms research and argued repeatedly for electronic systems, but his 
ideas were always rejected. Electronic systems were considered unreliable. 
But Flowers was unable to reveal that he had built machines with 1,500 
electronic valves. The fate of the nation had depended on their 
reliability.


http://www.timesonline.co.uk/newspaper/0,,175-2077902,00.html