Polybius Square Cipher
Polybius square cipher with interactive 5x5 grid
Polybius Square (I/J combined)
1
2
3
4
5
1
A
B
C
D
E
2
F
G
H
I/J
K
3
L
M
N
O
P
4
Q
R
S
T
U
5
V
W
X
Y
Z
About Polybius Square
The Polybius square is a device invented by the ancient Greek historian Polybius for fractionating plaintext characters. Each letter is represented by its coordinates in a 5x5 grid.
Since the Latin alphabet has 26 letters but the grid only has 25 cells, I and J are typically combined into a single cell.
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