@Miss Kitty: Hehe okies,
I typed this up a while ago and figured it was good for here too lol
Monoalphabetic ciphers and Polyalphabetic ciphers.
Polyalphabetic ciphers operate with more than one cipher alphabet, compared to the monoalphabetic ciphers.
An example of a monoalphabetic cipher would be the Caesar Shift, which is a substitution cipher in which each letter of the alphabet is replaced by the one three spaces on in the alphabet. Sometimes the spacing varies, so it can be nine spaces, or maybe even sixteen, but the standard is three. This is what a sentence encoded with the 3-space shift would look like:
L OLNH FDWV DQG GRJV. (I like cats and dogs.)
(A=D, B=E, C=F, etc.)
However, with a polyalphabetic cipher, another cipher alphabet enters the fray, to obscure the meaning further. I'll use the Rail-Fence transposition cipher, which mixes up the letters into two lines in a zigzag pattern and groups them into four.
(Some example somebody else made which I'm just using here lol)
So you have the plaintext "Defend the East Wall"
Which is then read top line first, then second line, so it reads as "DFNT EATA LEED HESW L(ZZZ)"
The end 'Z's are nulls to ensure that all letters are in a group of 4. Also, the spaces between the groups of four could also be padded with nulls, so it would read as DFNTZEATAZLEEDZHESWZLZZZ, though with the overuse of Zs, it may become a little obvious, if you are using it as a monoalphabetic cipher.
However, let us combine the Caesar example with the Rail-Fence, and we get this when we apply the Rail Fence over the already enciphered text made by the Caesar Cipher:
LLHD VQGJ ONFW DGRV
(If padded with nulls, LLHDZVQGJZONFWZDGRV).
....I could probably expand on this more right now but I'm worried about how long this post will look lol
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