Introduction: – In your previous chapter, you have learned about the different types of traditional ciphers. Also you have gone through two examples of such types. In this tutorial, you will traverse and learn more about these traditional cipher algorithms. So, lets begin.
Scytale Cipher: –
This is one of the oldest and most commonly used message hiding techniques. It is an old Greek cipher technique where you have to round the strip of paper in a round log. Then the message is written in another paper along the log staff row-wise, which forms the cipher text. This makes the cipher text a collection of meaningless random letters. The receiver of the message should have to use that similar log staff in order to decrypt the message.
Reverse Cipher: –
This is one of the most simpler form of ciphing technique used in the earlier days bu kings and soldiers. Here you have to just write all the letter of the plain text in reverse order, maintaining the space in between them as the plain text.
Plain Text: I conquered the north India
Cipher Text: a idnIhtron eht dereu qnocI
Row transposition Cipher: –
In this cipher technique, the plain text is first written under the column having specific numbers, and then you have to reorder the columns based on some key before reading the rows to convert to cipher text.
Here is an example:
Plaintext: attack has been postponed
which will be written as :
Casual: 2 4 1 3 6 5 7
No. a t t a c k h
a s b e e n p
o s t p o n e
d[u v w x y z]
For generating cipher text, you have to use the key to rearrange the set of letters.
Key: 4 3 1 2 5 6 7
t a t a k c h
s e b a n e p
s p t o n o e
u w v d y x z
Then read this row-wise, to convert it to fully cipher text. Something like this:
You might have noticed that we have added u-z as extra set of letters. That you can use as you will have lack of letter fulfilling the column location from the plain text, in those cases you can use the last set of letters of English alphabet.