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Cryptology
101 - Part 4
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<-- Back to the Caesarian
Square
Julius Caesar, as smart as he was, could not have left us
with only one method of concealment to his name. The great military
leader invented another method of encryption that was more secure
than the previous.
This method relies on letter substitution that is assigning
one letter to replace another when encrypting the message.
This method was more versatile as it did not limit the sender
to messages of perfect square length. It also made the message
harder to decode because each letter has 26 possible letters
that it could represent. If you were to try every possible
letter combination it would take longer than a lifetime to
crack the message; there are too many possible combinations.
Now let's use the Caesarian shift:
First we have to start by creating the "Shifted Alphabet."
Caesar preferred shifting his alphabet by three letters, however
you can shift by as many as you like, just make sure your
recipient knows how many you shifted by. For our example we
will use the standard three letter Caesarian shift method.
|
| Normal Alphabet |
Shifted Alphabet |
| A |
Y |
| B |
Z |
| C |
A |
| D |
B |
| E |
C |
| F |
D |
| G |
E |
| H |
F |
| I |
G |
| J |
H |
| K |
I |
| L |
J |
| M |
K |
| N |
L |
| O |
M |
| P |
N |
| Q |
O |
| R |
P |
| S |
Q |
| T |
R |
| U |
S |
| V |
T |
| W |
U |
| X |
V |
| Y |
W |
| Z |
X |
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As
you can see the alphabet has been shifted by three letters so
that the encrypted alphabet starts at the letter C.
Now we will encrypt this plaintext:
May the force be with you!
Once again we begin by removing all spaces and punctuation
from the message:
maytheforcebewithyou
Then you encrypt the message by substituting your plaintext
letter with its shifted alphabet partner revealing the ciphertext:
kywrfcdmpaczcugrfwms
Decoding the message is simple. Reveal the plaintext by
substituting the shifted text letter with the plaintext one.
This method may take more time, but is much more secure.
Next Learn To Write Codes Using a
Keyword -->
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