Enigma

Today I rebuilt an old computer that I could use to write the blog without having to be wired to the home local area network. As long term readers of the blog will know both of my Apple portables have be involved in accidents. The Mac Book has a broken screen and the iBook has a broken power supply, both accidents were Lucy related. The remaining Apple machine, a old Mac Mini doesn't have a wireless card making it hard to use in the living room.

Thankfully it doesn't take much processing power to write a blog. All you need is a computer you can go on the internet with. In this case a old single core Pentium IV class machine with a decent graphics card, a reasonable amount of memory, a small hard disk and an ancient wireless card. The trick is not to load it up with the latest operating system and expect it to be fast, but instead load it with a operating system and software that it was originally intended to use and watch it fly.

During the process of loading the operating system the original hard disk I was using failed and I had to use another disk that probably hadn't been used for 5 years looking at the date of the files that I backed up. It was one the hard disk of my main machine. On the disk was a simulation of an Enigma machine that was used by the Germans to code messages in the Second World War and lead to the construction of one of the worlds first computers. Emily was with me and I explained how it worked.

Codes have always fascinated for years and it is easy to devise simple codes you can use. The one thing about the Enigma code was it wasn't that easy to crack and without the work of some very great brains would have remained that way. Even the Boffin's at the famous Bletchley Park didn't manage to decipher everything. In fact, some of the coded messages weren't broken until over Sixty years after they were sent.

The enigma machines were a mixture of mechanical and electrical components. None of the computer components and mixture of electronics you would expect to find today. In order to show how it worked I typed in a simple message after setting the machine up and showed Emily the output:

GIDM TGXE WOYO GFYE NHEZ EHSX JCBU LNDN PWHU UYML GWBK UJCV GPRW URDE IFBX IWVO SQYO JSSY HPWB JGHS ICZU DKHJ Y

Then to show her how to decode the message I reset the machine and typed in the encrypted message and out of the machine came the original message as if by magic. It was part of the beauty of the system that the same machine could be used to encode and decode the message as long as you both had the same starting setup.

As someone that has always been interested in computing history, the story behind how the codes were cracked and how that lead to the construction of the first computers is a fasinanting one. Hopefully I manged to pass on some of that interest to Emily, who loves anything mathamatical. She seemed fasinated with the simulator and was soon entering her own messages and decoding them.