Polybius Square
uses a grid set sometimes with a password to scramble text to numbers
6x6 square example:
|
1 |
2 |
3 |
4 |
5 |
6 |
| 1 |
A |
B |
C |
D |
E |
F |
| 2 |
G |
H |
I |
J |
K |
L |
| 3 |
M |
N |
O |
P |
Q |
R |
| 4 |
S |
T |
U |
V |
W |
X |
| 5 |
Y |
Z |
0 |
1 |
2 |
3 |
| 6 |
4 |
5 |
6 |
7 |
8 |
9 |
Letters can be reference by the X/Y numbers to produce the cipher
Text: NICE DAY FOR A WALK
Result: 23 32 31 51 41 11 15 61 33 63 11 54 11 62 52
A more basic square can also be used for just the alphabet (5x5 square) with one letter being shared - usually I/J or C/K
The layout of the square is the "password" and has to be pre-shared.
5x5 Square exaple:
|
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 |
Text: NICE DAY FOR A WALK
Result: 33 42 31 51 41 11 45 12 43 24 11 25 11 13 52
The squares can be cracked by use of frequency analysis if the encrypted text is long enough.