ES slide
The ES-Schieber (spelling also: ES-Schieber or ES.-Schieber ) is a simple cryptographic device that was used by the German Navy during World War II to enable a distinction between friend and foe . In the military parlance of the Wehrmacht, the abbreviation ES generally stands for " identification signal ". It was also used in other parts of the Wehrmacht, for example in the army , for example in connection with signal pistols . A typical application example would be to respond to a green and then red flare as "ES" with red and white in order to identify yourself as a "friend".
The purpose of the ES slider was to cryptographically securely determine the identification signal (here: red and white) that was valid for authentication , without it being able to be accessed by the enemy or unauthorized persons.
principle
The ES slider is basically one of the most basic cryptographic devices, namely the encryption disk , as it was described by the Italian scholar Leon Battista Alberti in the 15th century . Since then it has been used again and again, for example in the American Civil War (see picture). More precisely, there are two circular disks of different sizes, mostly made of metal, which sit on a common axis and are connected in such a way that the smaller one can rotate on the larger one.
construction
The ES slider has a choice of two five discs, five large ( ⌀ 13 cm) and five small ( ⌀ 10 cm), which are in a cardboard box with a slotted wooden insert for transport and practical storage . The five large discs are identified by their first names, which all begin with the letter E: Eberhard, Egbert, Emil, Erasmus and Ernst. Each of these disks is divided into 58 equally sized sectors along its circumference . Here, the 31 days of the month are entered numerically in ascending order, but with irregular gaps, different for each disc. For example, with the “Egbert” disc, starting with | 1 | 2 | 3 | | | | 4 | 5 | | 6 | 7 | | | 8 | 9 | and so on.
The periphery of the five small disks is also divided into 58 circular segments of equal size. These have all the numbers from 1 to 58 in an irregularly scrambled arrangement and in red letters. The five small discs are identified by surnames that begin with the letter S: Schilling, Schmidt, Schneider, Schulze and Seidel.
Use one of five "first name discs" (E) together with one of the five "last name discs" (S), for example "Erasmus" and "Schulze". This designation has the advantage that you can easily remember the respectively valid combination for determining the ES like a personal name. Such a combination was typically valid for two to four days, with the change taking place at noon at twelve o'clock. This makes sense because ES were mostly needed during the dark.
application
The exact application was described in the secret marine service regulation No. 75 (M.Dv.Nr.75) "ES regulation". The NES40 procedure was used to detect larger ships at night. The abbreviation stands for Night Detection Signal 40. The method is based on two rows of lights arranged one above the other, which were clearly visible on every larger ship and which were controlled from the bridge. Each row could be illuminated independently in the colors red, white or green. A total of 3 x 3 or nine color combinations were possible.
A valid for the month key panel titled took "ES-setting" is, for the day setting for the ES-slide, such as "Erasmus Schulze," an ES key number as 35, and a letter. B. D, which designated the ES board to be used for the night detection signal. There was also a setting number, for example 28, which was valid for one month and to which the ES code number had to be set using the ES slider.
In order to use it, it was stipulated to put the small “Schulze” disk onto the large “Erasmus” disk of the ES slide. Then you had to turn the small disk so that the ES code number, here 35, as a red number with the setting number, here 28, on the large disk was aligned. For a certain date that you can now read off the outer number wreath, there was a red number to be read on the small disk, e.g. B. the "2". This number between 1 and 58 indicated the sequential number under which the color combinations to be used as a call or as an answer were recorded on the ES board. The ES board D indicates "2" as the call colors green-red and the answer colors red-white.
literature
- Niels Faurholt: ESSchieber German Code Device from WWII . Cryptologia . Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA. 2009, 34: 1, pp. 44–51, ISSN 0161-1194 , (contains photos from "Erasmus Schulze").
Web links
- Wehrmacht abbreviations . Retrieved February 4, 2015.
- Encryption according to Alberti . Retrieved February 4, 2015.
- German ES Code Disks (English) with photos by "Egbert Schneider". Retrieved February 4, 2015.
Individual evidence
- ↑ Abbreviations of the Wehrmacht ( Memento of the original from February 4, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed February 4, 2015
