I'm not sure of the prior history, which may affect my appreciation for it, but as far as I know, what happened with Colossus was that they were aware the cipher seeds changed each day, and they obtained an Enigma machine so they could decipher Enigma codes, it was the fact there was a reliance on intercepting the day’s seeds, or having a spy/double agent leak them which meant cracking Enigma messages was usefully impossible within the timeframe in which military strategies could be formulated and altered.
So Colossus brute-forced every combination of Enigma symbols and seeds until it got something that made sense.
Colossus did this in hours, instead of the weeks waiting for code breakers with brain-power and persistence alone, and to my knowledge this was the first application of computers as we recognise them today.
I find it amazing that Turing sat and thought to himself, in the 1940s, "I bet I can make a machine that does this", and built the thing, and built it so well it deciphered the codes within the day, before the seeds changed.
I'm sure a brute force on paper existed before Colossus, but Colossus is a stunning, visceral machine to watch.
Seeing Colossus operating is an absolute experience for computerphiles. There's something more soulful (in the laïc sense) in seeing a big wall of spinning disks and tape and reassuring thuds and whirs than in modern solid-state computers.
So Colossus brute-forced every combination of Enigma symbols and seeds until it got something that made sense.
Colossus did this in hours, instead of the weeks waiting for code breakers with brain-power and persistence alone, and to my knowledge this was the first application of computers as we recognise them today.
I find it amazing that Turing sat and thought to himself, in the 1940s, "I bet I can make a machine that does this", and built the thing, and built it so well it deciphered the codes within the day, before the seeds changed. I'm sure a brute force on paper existed before Colossus, but Colossus is a stunning, visceral machine to watch.
Seeing Colossus operating is an absolute experience for computerphiles. There's something more soulful (in the laïc sense) in seeing a big wall of spinning disks and tape and reassuring thuds and whirs than in modern solid-state computers.