‣ Tap code, sometimes called the knock code was reportedly invented by four POWs imprisoned in Vietnam and is sometimes called "Smitty Code" after Captain Carlyle ("Smitty") Harris. An Air Force instructor who had shown him a code based on a five-by-five alphabet matrix or Polybius square.
It is a code similar to Morse code, and it is commonly used by prisoners in Vietnam to communicate with one another. It uses a 5x5 square to assign two numbers (row and column) to each letter. Then the sender knocks as many times as each number, and makes pauses between the numbers.
1 2 3 4 5
1 A B C D E
2 F G H I/J K
3 L M N O P
4 Q R S T U
5 V W X Y Z
Example: "Hello"
- First translate it to numbers using the Polybius square:
H E L L O
23 15 31 31 34
Then translate them to dots:
2 3 1 5 3 1 3 1 3 4
.. ... . ..... ... . ... . ... ....
* * *
Plaintext - Ciphertext:
A • •
B • ••
C • •••
D • ••••
E • •••••
F •• •
G •• ••
H •• •••
I/J •• ••••
K •• •••••
L ••• •
M ••• ••
N ••• •••
O ••• ••••
P ••• •••••
Q •••• •
R •••• ••
S •••• •••
T •••• ••••
U •••• •••••
V ••••• •
W ••••• ••
X ••••• •••
Y ••••• ••••
Z ••••• •••••
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DECIPHER: A Compilation of codes and ciphers
Random✘ - - - DECIPHER is a book compilation that tackles different, new and old codes/ciphers. In addition, this book begins with the definition of cryptography along with it's different terminology for begginers, and better understanding. Interested? W...
