Slide Cipher

The slide cipher is one where each letter of the message is "slid" along the alphabet by a certain number of letters. For example, if we use a "+1" slide cipher, 'A' is swapped for 'B' (one letter on), 'B' is swapped for 'C', and so on.

A

B

C

D

E

F

G

H

I

J

K

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B

C

D

E

F

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A

However, if we use a "+3" slide cipher, 'A' is swapped for 'D' (three letters on), 'B' is swapped for 'E', and so on.

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

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Y

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D

E

F

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A

B

C

They are easy to use because all you need to decipher them is the number representing how much the message was originally "slid" by. We could pass the information at the start of the message, like this:

[3] L ORYH D VXQEXUQW FRXQWUB

It is easy to see that there are 26 different slide ciphers (although [0] doesn't change the message at all).

Try It!