This Easter holidays 'er indoors and I went to Bletchley Park, home of the cipher and code breakers of WWII.
Fascinating place with a lot of stories to tell. The place reeked of history populated by eccentric British "Boffins". Some of the guys working there as curators now actually worked there in the '50's and '60s when the place was still a central military establishment.
Have to say, the reverse logic, techniques involved plus some of the maths employed went right over my head.
Loads more to see than depicted on these photos, but for those that are interested.....
lots of enigmas (and variations to excuse the pun)
early luftwaffe

a four wheel army variant. This is the one that got stolen a few years back and was held to ransom

wiring the cog to the thingy.. this is where it started to get complicated


a set of encoding wheels

read the insert (a lot of the rotors thingies are actually the same as found in old fashioned telephone exchanges)

Colossus - rebuilding a replica of the original.
Ther are no full plans of the machine, Apparently the replica is based on 4 photograpghs of the original and 2 pages of engineering notes that should have been destroyed


The message to be decrypted is first loaded onto a paper tape (each row of punch holes corresponds to a single letter

and the tape stream is fed as an endless loop into colossus. The machine has no memory, so the data is continuouslly reloaded... this is 1943/44 remember

the paper strip runs at approx 30 mph

but he still has a lap top to check e-mail

This is a bombe, not a computer, but a mechanical machine that was used to help deduce the initial sequencing code that was used to encode enigma ciphers. The code was changed daily from one of several thousand million possible combinations. This machine did not crack it, but produceded possible combinations that it could be

the wiring at the back....

Will have to go back again to just start to understand how it works.
It really does boggle the mind to understand how they reverse engineered it.
G