|
|
|
|
Hand Caesar Switzerland ← Réglette
The device measures 30 x 3 cm and is made of eloxed aluminium. A lane is
milled-out at the centre over the full length of the device, in which a
tight fitting slider is placed. The fixed part has the Latin alphabet
engraved twice along the lower edge, in the normal A-Z order.
The slider has a single alphabet engraved in reverse (Z-A).
This effectively gives us a so-called
Reverse Caesar Cipher — much like the
Reverse Caesar cipher wheel
shown elsewhere on this website —
which has the advantage of being fully reciproke (reversible), even
when the alphabet is shifted.
|
|
|
The system is named after Julius Caesar (55 BC) who used it for his
private correspondence. Although Julius Caesar used a fixed offset between
the two alphabets — he shifted each letter of the plaintext 3 positions down
in the alphabet — the name Caesar Cipher is commonly used for all ciphers
which feature linear alphabet transposition. In practice, many variations are
possible.
A special variant of the Caesar Cipher is ROT13,
which shifts each letter by 13 positions (exactly half the available 26
letters of the Latin alphabet). It is often used in simple software, and
has the advantage to be reciproke: applying the ROT13 function to
the ciphertext, reveals the plaintext.
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
I
|
J
|
K
|
L
|
M
|
N
|
O
|
P
|
Q
|
R
|
S
|
T
|
U
|
V
|
W
|
X
|
Y
|
Z
|
Z
|
Y
|
X
|
W
|
V
|
U
|
T
|
S
|
R
|
Q
|
P
|
O
|
N
|
M
|
L
|
K
|
J
|
I
|
H
|
G
|
F
|
E
|
D
|
C
|
B
|
A
|
|
The Reverse Caesar Cipher used by the slide rule shown here, is yet
another variant, in which the sliding alphabet is ordered in reverse
direction. It has the advantage of being reciproke at any position
of the slider. This means that a single procedure can be used for coding
and decoding.
To make the cipher stronger, and hence more difficult to break,
a complex procedure involving key words and some calculations was used.
The exact procedure is described in the manual [A].
|
-
(EVU) = Eidgenössiger Verband der Übermittlungstruppen
(Federal Confederation of Signals Corpses).
|
-
Document kindly provided by Walter Schmid.
|
- Günter Hütter, Chiffrierschieber Cäsar — THANKS !
Photographed with kind permission. September 2017.
- Walter Schmid, Personal correspondence
December 2017.
|
|
|
Any links shown in red are currently unavailable.
If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Wednesday 10 January 2018. Last changed: Saturday, 28 May 2022 - 09:23 CET.
|
|
|
|
|
|