The follwoing is a OCR scan from "The Cryptogram" published by the American Cryptogram Association, July - August 1982, Vol XLVIII No 6, pages 4 and 5.
This page is being published with the kind permission of of the editor of The Cryptogram.

THE M-94 TEST MESSAGES

BY MEROKE

In 1917, Major (later Major General and Chief Signal Officer) Joseph 0. Mauborgne, developed the M-94, a 25-disk, cylindrical cipher device. Around the rim of each disk was a different 26-letter mixed alphabet that Mauborgne had composed to insure "that the fewest number of repetitions of pairs of letters ... would occur." Then, to test its security, he used one key, i.e., the order or arrangement of the disks, to encipher a series of 25 manages. On April 23, 1918, he sent the first 25 encrypted letters of each of the 25 messages to William F. Friedman at the Riverbank Laboratories and to Major Herbert 0. Yardley at the Cipher Bureau (MI-5) for cryptanalysis.

Neither Friedman nor Yardley had any success, and after considerable effort a request was received from Riverbank Laboratories for a word of plaintext. Mauborgne supplied two consecutive words, ARE YOU, from one of the messages, but even after trying these words in every possible position none of the messages was solved. As a result, Mauborgne's device was officially adopted by the United States Army in 1921.

Twenty years later, in 1941, after General Mauborgne had retired, Friedman found the plaintexts of the 25 test messages in a file in Mauborgne's old office, and the reason for their insolvability became evident. The, words were English, but most of them were unusual and seldom used, certainly not the type you would expect to find in military messages, which is what Friedman and Yardley had expected.

As a challenge to the krewe - with a prize - the ciphertexts that stumped the experts are provided on the next page. A copy of the new paperback edition of The American Black Chamber by H. 0. Yardley, with an introduction by David Kahn, will be awarded to the first person who sends me the plaintexts of all 25 messages with an explanation of how the solution was found. Of course, the solution is easier today than it was for Friedman and Yardley, because the jumbled alphabets used on the M- 94 are available whereas in 1918 they were not. So, to give everyone an equal chance, the 25 mixed alphabets used on the M-94 are also provided. Good solving.

THE 25 M-94 MIXED ALPHABETS DISKS

1B A B C E I G D J F V U Y M H T Q K Z O L R X S P W N

2C A C D E H F I J K T L M O U V Y G Z N P Q X R W S B

3D A D K O M J U B G E P H S C Z I N X F Y Q R T V W L

4E A E D C B I F G J H L K M R U O Q V P T N W Y X Z S

5F A F N Q U K D O P I T J B R H C Y S L W E M Z V X G

6G A G P O C I X L U R N D Y Z H W B J S Q F K V M E T

7H A H X J E Z B N I K P V R O G S Y D U L C F M Q T W

8I A I H P J O B W K C V F Z L Q E R Y N S U M G T D X

9J A J D S K Q 0 I V T Z E F H G Y U N L P M B X W C R

1OK A K E L B D F J G H 0 N M T P R Q S V Z U X Y W I C

11L A L T M S X V Q P N O H U W D I Z Y C G K R F B E J

12M A M N F L H Q G C U J T B Y P Z K X I S R D V E W O

13N A N C J I L D H B M K G X U Z T S W Q Y V 0 R P F E

14O A 0 D W P K J V I U Q H Z C T X B L E G N Y R S M F

15P A P B V H I Y K S G U E N T C X 0 W F Q D R L J Z M

16Q A Q J N U B T G I M W Z R V L X C S H D E 0 K F P Y

17R A R M Y O F T H E U S Z J X D P C W G Q I B K L N V

18S A S D M C N E Q B 0 Z P L G V J R K Y T F U I W X H

19T A T O J Y L F X N G W H V C M I R B S E K U P D Z Q

2OU A U T R Z X Q L Y I O V B P E S N H J W M D G F C K

21V A V N K H R G O X E Y B F S J M U D Q C L Z W T I P

22W A W V S F D L I E B H K N R J Q Z G M X P U C O T Y

23X A X K W R E V D T U F O Y H M L S I Q N J C P G B Z

24Y A Y J P X M V K B Q W U G L O S T E C H N Z F R I D

25Z A Z D N B U H Y F W J L V G R C Q M P S O E X T K I

4                                                    The Cryptogram

<BC Note: there was a typo on the last line that I fixed>
 
 

T h e 2 5 T e s t M e s s a g e s

1  VFDJL QMMJB HSYVJ KCJTJ WDKNI
2  CGNJM ZVKQC JPRJR CGOXG UCZVC
3  CSTDT SSDJN JDKKT IXVEX VHDVK
4  OZBGF VTUEC UGTZD KYWJR VZSDG
5  QIRMB FTKBY CGAQV DQCVQ AHZGY
6  VQWRM IHDHB RQBWU LKJCS KEYUU
7  SSEIQ DWHNH QHGIK HAADN GNFBY
8  VXDVX NIGJO PCOTN GKWAX YTNWL
9  QJRLH AWTWU CYXVM BGJCR SBHWF
10 DULPK UXMVL XFUPS ULRZK PDALY
11 DCAIY LUPMB NACQE OPTLH KKRGT
12 MGODT VGUYX NHKBE WPOUR VTQOE
13 TBVEB QDXGP LCPUY AVVBK ZEOZY
14 FIJDW WBKTY GBSMB PZWYP RRZCW
15 DYVPJ CLNXE SCMF0 YPIZF PEBHM
16 MYYTJ RFMEP PHDXP ODFZO WLGLA
17 EYKKD XHTEV TRXWK CJPSG MASCY
18 LGQLV HTUIP YAUGJ PGDLH UZTKV
19 BRKTJ RGGTB HMLXX FRHOA AZVWU
20 CDUDV DBZUA ELRPO SPUJD XRZWA
21 EUFBT TWNIY HHTNW QNFVE NYGBY
22 TUTVY NGLPG TYOLI HXZQT XSGOJ
23 PBTJC CJONJ UNIXB UAQBI WNIHL
24 VHNKR XVZMD KFHUY XRNDD KXXVM
25 NNHBF VQH0B LXCYM AKFLS SSJXG

JA82                                 5

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