This is a mod I’ve been working on for a while and at the same time trying to learn Python scripting and the not-so-straight-forward SH5’s menu editor in the process…
As well as doing some historical research on U-boats and their Enigma message system.
Firstly, I think the Enigma machine is pretty well known and doesn’t need any introduction.
Secondly, please understand that
this will be a hardcore mod and will not be for everyone’s taste! If you never used any Enigma simulator, there will be a learning curve associated with the operation of the Enigma machine and how to use the Kriegsmarine’s procedure for decoding messages. Some users might also find it boring having to set up the machine, type and decode messages.
Having said that, I believe this mod will bring more historical realism to the message system in SH5. It will appeal specially to people, like me
, who are interested in the Enigma machines used by U-boats during the war.
With this mod you’ll have to employ the same procedure used by real U-boat radio operators to decipher messages. For the purists who would argue that this is not realistic because it wasn’t the captain’s job to decipher messages, this mod will come with the convenient option of “not installing it”.
For historical accuracy and consistency, the terminology for settings, tables and documents will remain in the original German, but easy-to-follow instructions will be provided in English.
----------- Features:
1 - A fully working "Schlüssel M" model M4 naval Enigma:
It will be accessible through the radio operator’s menu:
The machine’s UI layout was inspired by Dirk Rijmenants’ popular Enigma simulator and has three configurations:
The closed cover view:
Opened cover view with rotor case:
The
Steckerbrett (Plugboard) view:
2 - Implementation of actual Kriegsmarine cipher networks used during the war:
The naval Enigma used different cipher networks usually divided geographically. U-boats were issued envelopes with their assigned cipher network settings before going on patrol. Each cipher had its own daily key settings which meant that messages sent to a cipher network in the Atlantic could not be decoded by receivers in the Mediterranean for example.
This mod will implement the following cipher networks in SH5:
Hydra (known to the British code breakers as Dolphin) - For U-boats in the North Sea, English Channel, Baltic Sea and the Arctic.
Triton (Shark)- U-Boats in the North and South Atlantic
Medusa (Turtle) - U-Boats in the Mediterranean Sea
Poseidon (Grampus) - U-Boats in the Black Sea - …hoping that somebody will finally put a playable Type II in SH5
Tibet (Sunfish) - U-Boats in the Indian Ocean and other distant waters
Your U-boat will be issued only envelopes with codes that are related to the area where you’re located.
3 - Implementation of the Kenngruppen system used by the Kriegsmarine for U-Boat messages.
In-game campaign messages will be delivered as four-letter groups cryptograms, such as:
XVUO CMNL LHAN IXWK TOJJ IGEG WASP KWGS NELC JPBX
HICF AZLY PUUD OXBX AEZM EUEK BYSJ MYYS XVUO CMNL
The procedure you’ll have to follow will be thoroughly explained in the mod’s manual, but basically you will have to use the first two four-letter groups or
Kenngruppen (indicator group) and:
- Do a couple of letter substitutions using tables;
- Use the
Kenngruppenbuch (indicator groups book) to figure out in which cipher network the message was sent;
- Set the machine with the daily keys for that network;
- Decipher a four-letter message key encrypted in the beginning of the message;
- Finally proceed to decode the message.
This is just a quick overview. Everything will be explained in detail with examples.
Some of the in-game key sheets and tables that are implemented:
1 - Substitution tables, used to decipher the indicator group:
Actual tables:
http://www.cryptomuseum.com/crypto/c...6/000/full.jpg
In-game tables:
2 - Kenngruppenbuch (indicator groups book)
Actual book:
http://users.telenet.be/d.rijmenants...uppenbuch1.jpg
In-game book:
3 - Envelopes with daily settings:
Actual envelope:
http://www.enigma.hoerenberg.com/gal...ope_Triton.jpg
In-game envelopes:
Actual key sheets:
http://users.telenet.be/d.rijmenants/pics/triton2.jpg
http://users.telenet.be/d.rijmenants/pics/triton1.jpg
In-game sheets:
4 - Schlüsselzettel - form used to decode messages:
Original:
http://www.enigma.hoerenberg.com/gal...ttel_03_WS.jpg
In-game form, with an actual decoded message:
(The first column is the received radio message, second column the deciphered abbreviated message, third column is where you write what the message means.)
You can read more about this procedure here (scroll down to Kriegsmarine Procedures)
http://users.telenet.be/d.rijmenants/en/enigmaproc.htm
…and here:
http://www.enigma.hoerenberg.com/ind...gruppen System
4 – An external message application to edit, add and encipher messages.
Modders will be able to add/edit messages as well as generate new randomized code sheets and tables. Guidelines will be provided on how to write short and abbreviated radio messages.
This mod will require TDW’s UI. Also note that not all messages will be enciphered, it’s intended for messages that are campaign related --it'll use the campaign_radiomessages.txt file.
I intend to release this mod with formatted messages relevant to the OHII campaign. Since I'll be busy with the mod itself on my free time, if anybody is interested and could help by providing information of in-game events that are related to the campaign send me a PM please.
This is still a WIP! There’s no release date yet!
I’ll be looking for beta testers later on.
Preferably people with experience using any Enigma simulator and already familiar with the Kenngruppen system.
You can read more about the naval Enigma here:
http://www.cryptomuseum.com/crypto/enigma/m4/index.htm
A video explaining the inner workings of the Enigma machine:
Here’s a documentary on the subject:
