M-209

The M-209 Cipher Machine

May 082013
 
2013 MRCG Event After-Action Report

Last weekend, the 18th annual meeting of the Military Radio Collectors Group was held in San Luis Obispo, California, at Camp San Luis Obispo’s NCO club. The event included equipment displays, presentations, field operations and a swap meet. I had a great time, and nearly every other comment I heard about this year’s meet was positive. I’m already looking forward to next year’s annual meeting, as well as the occasional field events we’ll probably have throughout the year.

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Apr 302013
 
Announcing the M-209 Cipher Machine Group

The M-209 Cipher Machine

Inspired by the Enigma World Code Group, I’ve just launched a similar group for M-209 enthusiasts. The home page is at this URL:

http://www.nf6x.net/m209group

It can also be reached from the “Groups” menu under my web page banner.

Please check it out if you are interested in exchanging M-209 cipher messages with other crypto enthusiasts.

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Apr 282013
 
M-209 Simulator Update: Now with Key List Generator

Small M-209 Key List Booklet Resting on Open Large Booklet

I’ve just released version 2013-04-28a of my command-line M-209 simulator. The major addition to this release is a new Python script which generates key lists with daily scheduled key changes. The generated key list collections include 365-366 plain-text key files which may be read, printed or loaded into my simulator, and plain text key lists for each month which may be viewed or printed. Also, if TeX typesetting software and some other related utilities are available, various PDF key lists will be generated for on-screen viewing or printing into either small or large booklets. Please note that I’ve changed the version numbering from the old major.minor format to a date-based format.

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Apr 262013
 
KSM + MRCG Joint Crypto Operation

Merrill’s Marauders Message Center in Burma. Photo courtesy of Merrill’s Marauders Association. Used with permission.

The annual Military Radio Collectors Group meeting at Camp San Luis Obispo is almost here! This year, I’m pleased to announce that we’ll be conducting a joint crypto-related operation with the Maritime Radio Historical Society’s Coast Station KSM. Here’s their announcement of the operation.

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Apr 242013
 
Looking for some Input on M-209 Key Lists

I’m working on a Python script which automatically generates a year’s worth of M-209 keying materials, with daily key changes. I hope that this script and its output will be useful for future M-209 activities, and add a more realistic flair to them.

Now, the big problem is that I’ve never seen actual M-209 key lists. I’ve come up with a plain text format for individual key tables, which I think I picked up from one of the M-209 technical manuals. I know that individual keys were identified by two-letter sequences called “key list indicators”. I know that keys were intended to be changed periodically, possibly daily (or possibly more or less often depending on activity level, but I’m sticking with daily for my purposes). I’ve seen a training film in which an M-209 key list is consulted, but the video transfer of the film is too blurry to make out useful details.

From these details, I’ve inferred what I think a key list might have looked like. I’m hoping to get some input from other crypto enthusiasts about the formatting, wording, etc.

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Apr 142013
 
Practical Use of the M-209 Cipher Machine: Chapter 5

This post is part of a series of posts describing practical use of the M-209 cipher machine. The series will cover operation of the machine, setting the cipher key, formatting of messages, ciphering and deciphering messages, dealing with transmission errors, practices to make cryptanalysis (code breaking) of messages more difficult, and generating new key tables.

This chapter covers recognition and deciphering of messages.

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Apr 132013
 
Practical Use of the M-209 Cipher Machine: Chapter 4

This post is part of a series of posts describing practical use of the M-209 cipher machine. The series will cover operation of the machine, setting the cipher key, formatting of messages, ciphering and deciphering messages, dealing with transmission errors, practices to make cryptanalysis (code breaking) of messages more difficult, and generating new key tables.

This chapter covers composition, encipherment and formatting of messages.

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Mar 312013
 
Practical Use of the M-209 Cipher Machine: Chapter 3

This post is part of a series of posts describing practical use of the M-209 cipher machine. The series will cover operation of the machine, setting the cipher key, formatting of messages, ciphering and deciphering messages, dealing with transmission errors, practices to make cryptanalysis (code breaking) of messages more difficult, and generating new key tables.

This chapter covers internal key settings of the M-209.

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Mar 242013
 
Practical Use of the M-209 Cipher Machine: Chapter 2

This post is part of a series of posts describing practical use of the M-209 cipher machine. The series will cover operation of the machine, setting the cipher key, formatting of messages, ciphering and deciphering messages, dealing with transmission errors, practices to make cryptanalysis (code breaking) of messages more difficult, and generating new key tables.

This chapter covers basic operation of the M-209.

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Mar 242013
 
A Collection of M-209 Key Tables

Inspired by the Enigma World Code Group page, I have created a collection of key tables for the M-209 cipher machine for use by collectors and cryptography enthusiasts. This publicly-available collection of key tables, much like the code sheets on the Enigma World Code Group site, provides a set of ready-to-use M-209 keying material for M-209 aficionados to use. Obviously, openly published key tables don’t provide any real security, but they can be used by hobbyists to exchange M-209 cryptograms without needing to generate and distribute keying materials first. These key tables can be used for educational and entertainment purposes.

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Mar 232013
 
Practical Use of the M-209 Cipher Machine: Chapter 1

This post is part of a series of posts describing practical use of the M-209 cipher machine. The series will cover operation of the machine, setting the cipher key, formatting of messages, ciphering and deciphering messages, dealing with transmission errors, practices to make cryptanalysis (code breaking) of messages more difficult, and generating new key tables.

This chapter covers cryptographic basics to help you understand the machine.

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Feb 192009
 
M-209 Simulation Software

After I added an M-209-B Converter to my collection, I decided to write a software simulation of it as a learning exercise. Here is the result: a command-line application, written in C++, which is able to encipher and decipher text just like a real M-209 machine does. In addition, my simulator can generate new random keys and automate parts of the message-handling process. I’m releasing my simulator under the GNU Public License in the hope that it may be useful, educational and/or entertaining.

Update: This software is now hosted on GitHub. See this post for details.

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Feb 192009
 
Converter M-209-B

Converter M-209-B is a compact, portable mechanical cipher machine which was used by United States military forces during World War 2 and the Korean War. Designed by noted Swedish cryptographer Boris Hagelin, about 140,000 of the M-209 series machines were built. Unlike the German Enigma machine, this machine does not require an electrical power source. The U.S. Navy referred to this machine as the CSP-1500.

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