The Playfair Cipher

Create a 5 * 5 rectangle with all characters appart from J
Example:
```
S E C U R
I T Y A B
D F G H K
L M N O P
Q V W X Z
```
Break plaintext in letter pairs and replace the letter J with I.
Convert text using the table
If two letters are on the same row or column replace them with the succeeding letters.
otherwise replace them with the letters at the corners of the rectangle.
Block size: two characters

Example:

A -> B
B -> I
O -> P
R -> U
T -> A
X -> V
L -> O
A -> I
N -> L
D -> G
I -> Y
N -> L
G -> H
X -> W