Homepage
Crypto
Index
Glossary
Enigma
Hagelin
Fialka
Nema
Voice
Hand
OTP
EMU
Mixers
Phones
FILL
Codebooks
Algorithms
USA
USSR
UK
Yugoslavia
Ascom
AT&T
Bosch
Datotek
Gretag
HELL
ITT
Motorola
Mils
OMI
Philips
Racal
Siemens
STK
Tadiran
Telsy
Teltron
Transvertex
TST
Spy radio
Burst encoders
Intercept
Covert
Radio
PC
Telex
People
Agencies
Manufacturers
• • • Donate • • •
Kits
Shop
News
Events
Wanted
Contact
About
Links
   Click for homepage
Reverse Caesar Cipher
Polyalphabetic cipher disc

This cipher wheel was made by Linge in Pleidelsheim (Germany). It is a variant of the well-known caesar cipher of which the order of the alphabet on the inner disc is reversed. This type of manual cipher system is also known as a Reverse Caesar Cipher. The manufacturing date is unknown.

The image on the right shows the cipher disc which is milled out of a solid piece of brass. It consists of a fixed outer ring in which the 26 letters of the Latin alphabet (A-Z) are impressed in clockwise order. The outer ring has a milled-out area that holds the movable inner ring.

The inner ring is held in place by a bolt at the center and has the 26 letters of the Latin alphabet impressed in counter-clockwise order. Also mounted to the bolt at the centre, is a movable ruler that can be fixed in any of 26 positions by means of a knurled steel screw.
  
Linge reverse caesar cipher disc

The only indication that the cipher disc is manufactured in Germany, is the name of the maker (Linge) and the city name (Pleidelsheim), which are impressed at the bottom. The disc does not have a serial number. A similar disc [3] is shown on the German Wikipedia page about the Caesar Cipher [1], but that one appears to be incomplete. It has an improvised bolt at the centre and the ruler is missing. Furthermore is has a hole at the top of the letter 'A' of the inner disc.

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 disc shown here is a variant of the Caesar Cipher, of which one alphabet is in reverse order. When applied to the Hebrew alphabet in a static manner, the reverse caesar cipher is known as Atbash [2]. In its basic form it is a simple substitution cipher (or: mono­alphabetic substitution), but as the inner disc is movable, it could be used as a polyalphabetic substitution as well. If we align the letter 'P' of the inner disc with the 'A' of the outer disc, the substitution is as follows:

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
P O N M L K J I H G F E D C B A Z Y X W V U T S R Q

The advantage of the Reverse Caesar Cipher is that it is reciproke (reversible), even when the inner alphabet is shifted. As a result, the same procedure can be used for coding and decoding.

Linge reverse caesar cipher disc Linge reverse caesar cipher disc Linge reverse caesar cipher disc, top view Unlocking the ruler Rotating the ruler Linge reverse caesar cipher disc Knurled edge Manufacturer name at the bottom
A
×
A
1 / 8
Linge reverse caesar cipher disc
A
2 / 8
Linge reverse caesar cipher disc
A
3 / 8
Linge reverse caesar cipher disc, top view
A
4 / 8
Unlocking the ruler
A
5 / 8
Rotating the ruler
A
6 / 8
Linge reverse caesar cipher disc
A
7 / 8
Knurled edge
A
8 / 8
Manufacturer name at the bottom

Help required
At present we have no further information about this cipher disc, its manufacturer or its age. If you have any additional information, please contact us.


References
  1. Wikipedia, Caesar-Verschlüsselung
    German. Retrieved September 2014.

  2. Wikipedia, Atbash
    Retrieved September 2014.

  3. Hubert Berberich, CipherDisk2000
    Image of Linge cipher disc. Via Wikipedia, Retrieved September 2014.
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Thursday 11 September 2014. Last changed: Saturday, 08 July 2017 - 08:45 CET.
Click for homepage