StateMaster - Encyclopedia: Reservehandverfahren

Reservehandverfahren (RHV) (German: Reserve Hand Procedure) was a German Naval World War II hand-cipher system used as a backup method when no working Enigma machine was available^[1]. The Kriegsmarine (or War Navy) was the name of the German Navy between 1935 and 1945, during the Nazi regime, superseding the Reichsmarine. ... Combatants Allies: â€¢ Soviet Union, â€¢ UK & Commonwealth, â€¢ USA, â€¢ France/Free France, â€¢ China, â€¢ Poland, â€¢ ...and others Axis: â€¢ Germany, â€¢ Japan, â€¢ Italy, â€¢ ...and others Casualties Military dead: 17 million Civilian dead: 33 million Total: 50 million Full list Military dead: 8 million Civilian dead: 4 million Total: 12 million Full list World War II... This article is about algorithms for encryption and decryption. ... A three-rotor German military Enigma machine showing, from bottom to top, the plugboard, the keyboard, the lamps and the finger-wheels of the rotors emerging from the inner lid (version with labels). ...

The cipher had two stages: a transposition followed by bigram substitution. In the transposition stage, the cipher clerk would write out the plaintext into a "cage" — a shape on a piece of paper. Pairs of letters were then substituted using a set of bigram tables^[2]. In classical cryptography, a transposition cipher changes one character from the plaintext to another (to decrypt the reverse is done). ... Bigrams are groups of two written letters, two syllables, or two words, and are very commonly used as the basis for simple statistical analysis of text; one of the most successful language models for Speech Recognition (Collins, 1996). ... In cryptography, a substitution cipher is a method of encryption by which units of plaintext are substituted with ciphertext according to a regular system; the units may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. ...

The Reservehandverfahren cipher was first solved at Bletchley Park in June 1941 by means of documents captured from U-boat U-110 the previous month. Thereafter it was solved using cryptanalysis for over three years. Some 1,400 signals were read during that period, an average of 12 per day. The section working on RHV was headed by Historian Sir John H. Plumb. The decrypts were sometimes useful in themselves for the intelligence that they contained, but were more important as a source for cribs for solving Naval Enigma^[2]. During World War II, British and American cryptographers at Bletchley Park broke a large number of Axis codes and ciphers, including the German Enigma machine. ... Unterseeboot 110 (U-110) has been the designation of two submarines of the German Navy. ... Cryptanalysis (from the Greek kryptÃ³s, hidden, and analÃ½ein, to loosen or to untie) is the study of methods for obtaining the meaning of encrypted information, without access to the secret information which is normally required to do so. ... In cryptanalysis, a crib is a sample of known plaintext; the term originated at Bletchley Park, the British codebreaking operation during World War II (WWII). ...

A Mediterranean variant was known as Schlüssel Henno, which was first tackled — unsuccessfully — in May 1943. It wasn't until after a capture of cipher documents from a raid on Mykonos in April 1944 that the Naval Section was able to read Henno. With over 1,000 signals a month, up to thirty people were assigned to solve the messages. The work was abandoned in August 1944 after it was found the intelligence value of the decrypts was "rather disappointing"^[3]. Satellite Image of Mykonos Mykonos (Greek: ÎœÏÎºÎ¿Î½Î¿Ï‚; see also List of traditional Greek place names) or Myconos is an island of Greece. ...

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Category: Classical ciphers In cryptography, the ADFGVX cipher was a field cipher used by the German Army during World War I. ADFGVX was in fact an extension of an earlier cipher called ADFGX. Invented by Colonel Fritz Nebel and introduced in March 1918, the cipher was a fractionating transposition cipher which combined a... The Affine cipher is a special case of the more general substitution cipher. ... Atbash is a simple substitution cipher for the Hebrew alphabet. ... An autokey cipher, or self-synchronizing stream cipher, is a cipher which incorporates the message (the plaintext) into the key. ... In classical cryptography, the bifid cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion. ... A book cipher is a cipher in which the key is the identity of a book. ... The action of a Caesar cipher is to move each letter a number of places down the alphabet. ... The Four-square cipher is a manual symmetric encryption technique. ... Hills cipher machine, from figure 4 of the patent In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. ... -1... In classical cryptography, a permutation cipher is a transposition cipher in which the key is a permutation. ... The Pigpen Cipher is a simple substitution cipher exchanging letters for symbols, using a grid. ... The Playfair system was invented by Charles Wheatstone, who first described it in 1854. ... A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets. ... The Reihenschieber was a hand cipher system used by Germany. ... In classical cryptography, the runnning key cipher is a type of polyalphabetic substitution cipher in which a text, typically from a book, is used to provide a very long key stream. ... In cryptography, a substitution cipher is a method of encryption by which units of plaintext are substituted with ciphertext according to a regular system; the units may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. ... In classical cryptography, a transposition cipher changes one character from the plaintext to another (to decrypt the reverse is done). ... In classical cryptography, the trifid cipher is a cipher invented around 1901 by Felix Delastelle, which extends the concept of the bifid cipher to a third dimension, allowing each symbol to be fractionated into 3 elements instead of two. ... The Two-square cipher is a manual symmetric encryption technique. ... The VigenÃ¨re cipher is named for Blaise de VigenÃ¨re (pictured), although Giovan Batista Belaso had invented the cipher earlier. ... In mathematics, physics and signal processing, frequency analysis is a method to decompose a function, wave, or signal into its frequency components so that it is possible to have the frequency spectrum. ... In cryptography, coincidence counting is the technique (invented by William F. Friedman) of putting two texts side-by-side and counting the number of times that a letter appears next to itself in both copies. ... A cryptogram is a type of word puzzle popularly printed in some newspapers and magazines. ... In cryptography, the Polybius square is a device invented by the Ancient Greek historian and scholar Polybius, described in Hist. ... This article is about the encryption device; for the Dune character, see Scytale (Dune). ... In cryptography, a straddling checkerboard is a device for converting an alphabetic plaintext into digits whilst simultaneously achieving fractionation (a simple form of information diffusion) and homophony (a simple method for suppressing peaks of the frequency distribution). ... Tabula recta In cryptography, the tabula recta is a square table of alphabets, each one made by shifting the previous one to the left. ...

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