Since we published the collection of unbroken German Army messages from 1941, a few of these messages have been broken. So far the keys for two days have been recovered; one of these messages was broken by a member of the M4 Message Breaking Project, Kevin Acres. Instead of waiting until the messages have been cleaned up and put into a format suitable for publishing, we have decided to release the Enigma keys first. In this way those of you who wish to hone their decoding skill have the opportunity to work on the real messages including garbles and other errors. We are convinced this will be a unique learning experience for those who want to get a feeling for what went on in Hut 3 at Bletchley Park during the Second World War.
For the readers who would like to try their decoding skills we should like to mention a few important point. You can use any Enigma simulator that has been certified to be correct in the sense that it uses the correct wheel wiring and also very important, that handles the Enigma stepping correctly. First of all you have to set up your Enigma machine with the correct wheel order and Ringstellung. You then have to make the Stecker connections for that day. You are now ready to decipher a message. In the Enigma keys below we also give the message key, the starting position. You find the corresponding message keys under the column, Start. However, to get a real feeling for it you should recover the message key yourself by first setting the machine to the Grundstellung, the first group of the indicator, and then decipher the second group of the indicator. As an example we will take message Nr. 23, KHLPT, of 8 July 1941. Here the indicator is the two 3-letter groups, OKF QLV. Setting the Enigma wheels to OKF you then decipher the second group, QLV, which will give you PIK. You then set your Enigma machine to the starting position PIK. You are now ready to decipher message Nr. 23. The message starts: KHLPT CWSEB DDIRB ZUUBG, but the first group, KHLPT, does not belong to the cipher text. It is the discriminant, Kenngruppe, which tells the cipher operator which Enigma key has been used to encipher this message. You therefore have to start deciphering the from the second group, CWSEB. From here you are on your own. We wish you the best of luck.
For further information about our codebreaking project see our Web Portal: Breaking German Wehrmacht Ciphers.
8 July 1941
Enigma keys for 08.07.1941
UKW : B W/O : 432 Stecker : CY, EL, FH, GS, IJ, KQ, MW, PV, RZ, TU Rings : PKF Message keys: No: Part: Kenngruppe: Indicator: Start: Stop: 23 KHLPT OKF QLV PIK PMA
3 October 1941
Enigma keys for 03.10.1941
UKW : B W/O : 213 Stecker : BC, DE, FG, HI, JK, LX, MQ, NO, ST, VZ Rings : TIP Message keys: No: Part: Kenngruppe: Indicator: Start: Stop: 4 NKMOW DTI AZZ SEE SKJ
All rights to the material described on these pages belong to
Geoff Sullivan & Frode Weierud, © April 2006
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