Code Chart Instructions

This code chart has been used for secure communications. Note that 
each cell in the matrix can be identified by four separate pairs of 
letters, starting with one letter from the left side of the matrix, 
then the second letter from the top of the matrix square.

For instance "Artillery" can be encoded as TF or TI or QF or QI.

Multiple codegroups provide twice the number of cell meanings and 
makes it harder for someone else to break the code.

If you need to send numbers, or a word not on the chart you can spell 
it out, using the alternative Spell/fig values in each cell.

For instance: choosing the same cell as above and meaning to send 
the alternate Spell/Fig meaning of "16" you would need to do a 
"Spell/fig Begins", MU or MV or HU or HV then one of the same four 
examples as above (TF, TI, QF,QI) to send "16" instead of "Artillery".
Don't forget to send "Spell/fig Ends" when going back to sending words.

A knowledge of the words available on the chart will help you compose
messages using mainly these words and thus keeps spelling to a minimum. 
This also makes the message much shorter and easier to transmit.

Besides - the most time this type of code is broken, is through the 
analysis of syllabary spelling of words not included in the matrix. 

See Chapter 15, Field Manual FM-34-40-2, Basic Cryptanalysis

For operational use, keep the 13 X 13 matrix the same. However change 
the order of the 26 letters in the left column and on the top row 
to make a totally different code system. Each day should have a 
different row and column for additional security.

This chart has been definitely worded for military usage.

Personalize the chart to be better suited for your own missions by 
choosing words which you would normally send and removing the words 
from the cells which you would probably never use in your operation.

The main point is once standardized, keep the 13 X 13 matrix the same.
Changing the matrix only hinders the code operators. Different codes 
are made by changing the order of the 26 letters in the row and column.
Keep the internal matrix the same.





For instance - the message:

"Attack the hill tonight and return before morning."


Could be encrypted as:

TT MU JY XR UU PE VO HV MX GK JG VG ES BJ TZ XT ET LK YU NA MV YY


TT               MU                JY  XR  UU               PE    VO
Attack,ed,ing,s  Spell/fig Begins  T   HE  Spell/figs Ends  Hill  Tonight

HV                MX   GK  JG  VG  ES  BJ  TZ  XT  ET  LK  YU              NA
Spell/fig Begins  AND  RE  T   U   R   N   BE  F   OR  E   Spell/fig Ends  Morning

MV                YY
Spell/fig Begins  Period

    *****Other Variations in Spelling Are Possible!*****

Note that the two duplications - Spell/fig Begins & Spell/figs Ends

MU / HV / MV  and   UU / YU

used different code groups each time - as to not stand out,
even though they stood for the same meanings!

  (If I had made the chart I would have not have Spell/fig Begins and 
  Spell/figs Ends in either the same row or column as each other. 
  I would place Spell/fig Begins in the Upper Left corner and 
  Spell/figs Ends in the Lower Right corner. 
  This would have provided the following results, using the same table:
  MC / MD / HC  and  UB / YA.
  Most often when a code chart is broken it is by analysis of spelling of 
  words which are not included in the chart.
  In higher level traffic the Spell/fig Begins and Period. could provide
  easy insight to the system, as many messages would include and end with
  them. Thusly I would have included the Period. as a word group.
  If the wordage of the chart would allow nulls to be  provided this 
  could further frustrate codebreakers. 
  Given enough time and traffic They Will Get Your System Anyhow!)


This message should be sent as five letter groups in the format:

11223 34455 66778 89900 11223 34455 66778 89900 11223 34455 >>>>>

So it would look like this:

TTMUJ YXRUU PEVOH VMXGK JGVGE SBJTZ XTETL KYUNA MVYYX

If the last group does not come out to an even five, use random letters 
to fill in and complete the last five letter group. Just be sure that your 
random letter/s do not change any intended meaning of the message. The YX on
the end might throw off some one who tries to match it up with the YX in 
the second group.
 





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