TUCoPS :: Crypto :: americ~1.txt

American Vietnam P.O.W. Code

                                Combat Arms
                              2869 Grove Way
                   Castro Valley, California 94546-6709
                         Telephone (415) 538-6544
                              October 2, 1988

                    American P.O.W. Communication Codes

     During the ugly period of time when Americans were held prisoner by
the North Vietnamese, they would communicate with their fellow prisoners by
means of a code tapped out on the pipes or on the walls. This enabled them
to keep hope alive, engage in the necessary practice of communicating with
other human beings, as well as share the latest news.

     Many have asked me why they simply didn't learn and use Morse code.
The problem with Morse code is that it consists of both dots and dashes.
When you have only a small rock or your spoon to generate the noise, the
matter of creating dashes becomes obvious. If there is no way to easily
distinguish the dots from the dashes, then Morse code must be ruled out.

     Therefore a simple code consisting of a series of taps (or dots, if
you will) is used. A matrix or box 5 characters wide and 5 characters long
is used to separate the letters, giving the prisoner an alphabet of 25
characters. The letter K is not used. The letter K sounds like the hard C
("kuh") and the person receiving the message should be bright enough to
figure out that "centucy" means Kentucky or the "cnife" means knife. Here's
what the box looks like:

                         1     2     3     4     5
                    1   A    B    C    D    E  
                    2   F    G    H    I    J  
                R     把陳陳田陳陳田陳陳田陳陳田陳陳
GROUP 1         O   3   L    M    N    O    P  
                W     把陳陳田陳陳田陳陳田陳陳田陳陳
                    4   Q    R    S    T    U  
                    5   V    W    X    Y    Z  

     To find a particular letter, you look up its Row number and then its
Column number. Where the two intersect, you will find the letter. For
example, if you start from the left at Row 1 and come down from the top at
Column 2 you will be at the letter B. To send a B, you would send its Row
and Column coordinates (1 and 2). You would tap once for the Row, pause,
and then tap twice for the column. The person receiving this would know you
were sending the letter in Row 1, Column 2. That would be the letter B.
After sending the column number (2), you would pause and start the second
letter. At the end of each word, pause a little longer. A long series of
taps (greater than 5 taps) would indicate that you made and error and that
the material following was correct.

       When the person on the receiving end hears you complete a full word,
he/she would send a quick two taps. This serves as feedback to you that the
person is still with you and following the communication. If the person
receiving the message has received enough letters to determine the word,
he/she should send a quick two taps to let you know that you can proceed to
the next word. 

     If the captors holding you prisoner break your code, it is a simple
matter of rearranging the letter sequence in the box to have a new code
base. That requires the rest of the prisoner population to have previously
been told of the method used to rearrange the letter in the box and the
signal (usually using the original arrangement of the letters) that the
person receiving the code should use the new arrangement. For example, you
may decide that the following should be used:

                         1     2     3     4     5
                    1   C    D    E    F    G  
                    2   H    I    J    L    M  
                R     把陳陳田陳陳田陳陳田陳陳田陳陳
GROUP 2         O   3   N    O    P    Q    R  
                W     把陳陳田陳陳田陳陳田陳陳田陳陳
                    4   S    T    U    V    W  
                    5   X    Y    Z    A    B  

     It is even better if there is a logic to the letter arrangement. For
example, you might decide to call the "regular" arrangement of letters in
the box "Group 1." Group 2 might be arranged so that the first letter of
the box would be the number of the month with the rest of the letters
following in their regular order. For example, if it were March (3rd
month), then the third letter in the alphabet (C) would be at Row 1, Column
1. The letters following would be in their regular order. This is what has
been done in the second example. November (the 11th month) would cause L to
be in Row 1, Column 1. You would then tell the person receiving the code to
"use group 2" and give them a few minutes to mentally calculate the letter
arrangement. They should not draw the box out unless it was in dirt that
could be quickly destroyed.

     Too simple? Right, because complex things are easily confused or
forgotten. If you wanted to increase the complexity, you could arrange the
first three letters to equal the three letter abbreviation for the month.
If it were July, the box would look like this:

                         1     2     3     4     5
                    1   J    U    L    A    B  
                    2   C    D    E    F    G  
                R     把陳陳田陳陳田陳陳田陳陳田陳陳
GROUP 3         O   3   H    I    M    N    O  
                W     把陳陳田陳陳田陳陳田陳陳田陳陳
                    4   P    Q    R    S    T  
                    5   V    W    X    Y    Z  

     Prisoners would be required to know something simple, like the month,
in order to determine the correct box layout.

     If you use common abbreviations, by dropping vowels or at least some
of them, then the code is more difficult to break by someone whose native
language is different from yours. Notice that I said "difficult," not
impossible. The purpose of the code is to permit communications when speech
is not possible. It is not the purpose to maintain utmost secrecy in these

     The variety of methods to transmit this code are not limited to
tapping on a wall or pipe. Body movements can send code, such as a finger
apparently idly tapping on a desk, blinking, head nodding, the beat of a
broom as it is used to sweep floors, etc. Shrugs can mean acknowledgement,
scratching one's nose can mean "no," pulling the ear lobe can be used to
signify "yes," etc.

     With a minimum of practice, you can become quite proficient. Be
careful not to develop the bad habit of sending faster that the other
person can receive the information.

     If you have other suggestions, please let me hear about them. Thank
you and I hope you never have to use this material. Here is a message for
you to translate using the Group 1 box. Each dot represents one tap. There
is a single space between the two elements making up the letter (... .....
means the letter P), three spaces between complete letters and eight spaces
between words.

.. ..   ... ....   . ....        . ..   ... .   . .....   .... ...

.... ...        . .   ... ..   . .....   .... ..   .. ....   . ...   . .

     Here is another message also using the Group 1 box.

.... ....   .. ...   . .....   .... ..   . .....        . .   .... ..

. .....        ... ...   ... ....        . ....   . .....   ... ..

... ....   . ...   .... ..   . .   .... ....   .... ...        .. ....

... ...        . .        .. .   ... ....   ..... ...   .. ...   ... ....

. ...   . .....

     Finally, let's pretend it is July and that we are using code Group 3
for our communications.

.... .   .. ...   . ....   .. .   .. ...        .... .....   ... .

.... ...   . ..        .... ....   . ..   .... .   .. ...   .... ...

... ..   ... .....   .... ...        .. ....   ... ..   .... ...   .. ...

.... .   ... .....   ..... ..   .. ...   .... ...

Richard M. Bash
Owner - Combat Arms
Castro Valley, California
Open 10 a.m. - 6 p.m. - Tuesday thru Sunday - Closed Mondays

Answers: (1) God bless America
         (2) There are no Democrats in a foxhole
         (3) Peace thru superior firepower

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