German Field Cipher (1918) - ADFGVX
Description
At first, the text is encoded using a checkerboard
cipher. For example, using the substitution key word KEY
we may obtain::
|
A |
D |
F |
G |
X |
| A |
K |
E |
Y |
A |
B |
| D |
C |
D |
F |
G |
H |
| F |
I |
L |
M |
N |
O |
| G |
P |
Q |
R |
S |
T |
| X |
U |
V |
W |
X |
Z |
The text MESSAGE is represented by FF AD GG GG AG DG AD.
This is now enciphered using an irregular columnar
transposition using a different key. For example, using the transposition
key word WORDS we obtain:
| W |
O |
R |
D |
S |
| 5 |
2 |
3 |
1 |
4 |
| F |
F |
A |
D |
G |
| G |
G |
G |
A |
G |
| D |
G |
A |
D |
|
This gives the final result as DADFG GAGAG GFGD. The cipher can
be used with 25 or 36 letter alphabets. When used with 36 letter alphabets,
the checkerboard coordinates are ADFGVX.
To proceed, you may