Coding and Deciphering_Communications

The1st Kuala Lumpur
Boys’ Brigade Company

Communications

21th July 2012 1

The Process of
COMMUNICATION
Noise

Encoding Message Decoding
Sender Receiver
Message Channel Message

Message
Channel

1st KL Communication Class - Advance 2

THE ENCODING
… is a system every word or phrase in your message is
replaced by another word, phrase, or series of symbols

A cipher is a system where every letter of your
message is replaced by another letter or symbol


The Encoding
Secret code and ciphers are also involved in
serious situations like in wars. People
will want to break codes and ciphers to
find out what the message is.


CONTENT
1.0 Codes 2.0 Word Clue Code 3.0 Ciphers

1.1 Book Code 3.1 Caesar Cipher

1.2 Dictionary Code
1.3 Pig Latin
1.4 Turkish Irish

4.0 St. Cyr. Slide 5.0 Concealment
4.1 Keyboard Cipher 5.1 Space Code
4.2 Date Shift Cipher
4.3 Combining Ciphers


1.1(2) CODES – Book/ Dictionary Code
1 Get 2 books that are the exact same thing.
They must be the exact
same, the same copyright date, the same
words, letters, language, everything, or else it will ruin this code. Now, hand a copy of the book to your
partner and you will use the other one. (Dictionaries work best).


2 Coding the Word
For example, you want to say "These pictures were in a book." well, you will have to search for these words in the
book.

Say like the word "These" is on page 212. Well, the first 3 digits of your code is 212. Then, you find the row of words.
For example, the word "these" is in row 4 of the book you are using.

So now your code is 21204.

Notice how I put the 0 in front of the 4 to make it a 2-digit number.

Now, say that "these" is the 7th word in the 4th row on page 212. Your code will be 2120407.
Using this code, every code should have 5, 6, or 7 digits (depending on if the book has 1000 pages or more; 9 or less rows; or 9
or less words in each row).



3 Test it out with a partner.
Once you learn this simple but effective code, it will be really hard
for an enemy to break it.


1.3 CODES – Pig Latin
1 Identify words that begin with a vowel (vowels vary within
language to language).
If it does, simply add "ay" to the end of the word. For example, ear becomes earay, arch becomes archay, and insulation
becomes insulationay.

2 Identify the words that begin with a consonant.
If it does, move the first letter of the word to the end and add "ay." If the initial consonant sound is made up of two
letters, like TH and CH, you move both to the end and add "ay."

For example,
trunk becomes unktray,
glasses becomes assesglay
measles becomes easlesmay


1.4 CODES – Turkish Irish
1 Simply put ab before the first vowel of a word.
Again, just like Pig Latin, this code works best when spoken. Identify the words that begin with a consonant.

For example
feet becomes fabeet
grudge becomes grabudge
Brigade becomes Brabigade


2.0 WORD CLUE
This code is simple (yet easy to break). Certain words are
instructions, like
'meet me at the book mixed-up hops',
which means
'meet me at the book shop' because 'hops' scrambled is 'shop'.

You could do 'reversed', making a word spelled backwards;
'scrambled' or 'mixed-up',
meaning to anagram it; or 'sounds like' meaning the word sounds like it.

Unless you are using a sandbox, this code is too easy to use to fool
people, and complex variations will have to be used in order to counter this
problem. You also need to prove that this zzbz sgssbs xhsa (code) will be
understand


3.0 CIPHERS
Understand what a cipher really is. What kind of cipher do you want to
use? There are only two (2) types of ciphers you could use:

Transposition & Substitution.
Both have their advantages and disadvantages.

• Substitution ciphers are easier to break, but transposition
ciphers are not as easy to use. A substitution cipher is that you
substitute one letter and replace it with another letter or symbol.

• Transposition cipher is where you transpose or rearrange
the position of the letters.


3.1 Caesar Cipher
The Caesar Cipher shifts the alphabet 3 places.
A becomes X
B becomes Y
C becomes Z, and so on.
So if you were to write
“Meeting tomorrow at station,"

you would write it as
“Jbbqfkd qljloolt xq pqxqflk.”


3.1 Caesar Cipher

Come for band
practice tomorrow!

ABCDEFGHIGJKLMNOPQRSTUVWXYZ

Zljb clo yxka
moxzqfzb qljloolt!


4.0 St. Cyr. Slide
The St. Cyr. you were able to shift the alphabet as many
places as you wish.

You can shift the alphabet so that A becomes K, B becomes
L, and so on. Or you could say that A becomes B, B becomes
C, and so on.


4.1 KEYBOARD CIPHER
Get a keyboard, and make sure that it has all 26 letters of the
alphabet.

You will need a QWERTY type because keyboards from different
countries will have different letters.

You can shift the keyboard to one letter space to the left, so on
your keyboard, H becomes G, F becomes D, and A becomes L
("turn over to the other side").


4.1 KEYBOARD CIPHER

Call me as soon as possible

Xlkk nw la aiin la oiaauvkw


4.1 KEYBOARD CIPHER


4.2 DATE CIPHER
1 Identify a Date
Steven Spielberg's birthday: December 18, 1946

2 Abbreviate the Date
Change the date to MM/DD/YY – 121846

3 Decode Message using date
Assume the message is
I enjoy the movies of Steven Spielberg
1 21846 121 846121 84 612184 612184612

4 Shifting the Letters
Shift each letter of the plain text by the number of spaces indicated by the number below it.

The letter I shifts one space, making it J;
E shifts 2 spaces, making it G. Your final message would be:

J gorse ujf usbjgt wj yugwmr yqkftfksi.

4.3 COMBINE CIPHER
You can also apply several ciphers to each other, thus creating
a stacked cipher.


5.0 CONCEALMENT
Codes and ciphers DO NOT conceal messages; they
REPLACE it. Concealment is different because the
message can be revealed, but is hidden.

Concealment works much better if a string of words
make sense with each other, making a legitimate
sentence. Doing this will fool people much longer than
nonsense words.


5.1 Space Code
A space code is moving the space to another place in a
message.

For Example the message
"I am your friend" could be Ia myou rfr iend.

Again, this is a code where you will have to speak
it to conceal it. If you write it down, a person
could easily find out the message by looking
at it from a relatively long distance from the paper.


5.1 Space Code

I h o p e y o u h a ve e n j o y e d t
h i s l e s s o nt h a n k y o u

I h o p e y o u h a v e e n j oy e d
this lesson thank you


The End


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