Alan Turing Cryptanalysis Papers

GCHQ, the UK government’s communications headquarters, has released two new—well, 70 years old, but new to us—cryptanalysis documents by Alan Turing.

The papers, one entitled The Applications of Probability to Crypt, and the other entitled Paper on the Statistics of Repetitions, discuss mathematical approaches to code breaking.


According to the GCHQ mathematician, who identified himself only as Richard, the papers detailed using “mathematical analysis to try and determine which are the more likely settings so that they can be tried as quickly as possible.”

The papers don’t seem to be online yet, but here’s their National Archives data.

EDITED TO ADD (5/12): The papers are available for download at GBP 3.50 each.

Posted on April 23, 2012 at 6:18 AM7 Comments


Clive Robinson April 23, 2012 7:51 AM

The Nattional Archives at Kew are unfortunatly required under current UK policy to attempt to “cover their costs” from their resources so they tend not to put as much on line as they might otherwise do.

If you want to know more on getting copies etc,

And yes it does say 167,000 meters of shelf space in that FAQ, if you ever visit the buildings from the outside you get that “throw back” feeling as though you have just steped on a “Blake’s Seven” or “Dr Who” film location representing a hedquaters of a totalitarian government.

And yes it’s most definatly worth a vist I’ve found it actually very nice and much more welcoming than the British Library up in central London.

You don’t need to book but for some documents you should check ahead as to their availability and in what form as you might need to have a readers card for seeing documentss in the original form

They also do events and themes, as you would expect they currently have stuff up on display about the Titanic.

Any way if you do plan to visit start with this link,

Hernan Coronel April 23, 2012 8:40 PM

Hi Guys at National Archives at Kew! Don’t you know that using adwords and a bit of creativity you can place data online and actually make more money than with physical visits? Google should get involved and put this guys out of their (seemingly totalitarian) missery.


Mike May 1, 2012 12:17 PM

Ryan, could you provide us a link? Or only people who can find it deserve to read it? ::::grin:::::

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