In Cryptography, the systems with repertories are systems of substitution which rest on the use of tables of correspondence or quantified dictionaries. The elements of these tables are represented in the form of letters, of syllables, words or sentences. Of an important size, these lists are impossible to retain by heart and must thus be written to form a work that one can name with choice:

• code

• repertory
• dictionary quantified
• table of coding.

Defects

Their obvious and irreducible defect is to exist with the state of printed book more or less bulky, but prone at a loss, flight or copy. The history of the chief of staff of Osman-Pasha during the Russo-Turkish war of 1877, left in round of inspection by carrying the secret code while its unhappy general-in-chief received dispatches without being able to translate them, remained famous.

A happy knack of a PC of battalion, the excavation of a captured or killed officer, without speaking about the codes copied by spies in times of peace, can bring back a code at the enemy, and become thus useless. A code contravenes thus the second Principe of Kerckhoffs.

Advantages

On the other hand, their advantage is to be of an employment simple and fast, and not very error prone if it is used by a sufficiently careful person. In addition, with the use of 4 or 5 symbols (that the Administration of the Telegraphs taxed only for one word), one can appear a whole sentence, much more expensive to transmit: from where the success of these codes in the trade and finance, where the secrecy often does not have an importance as considerable as in diplomacy or with the armies.

Cryptanalyse and uses

It is Antoine Rossignol, large specialist in the codes and their analysis, which is regarded as the author of the first great disordered repertories, such the “Grand Figure” of Louis XIV which will resist more than two hundred years the deciphering before being broken by Etienne Bazeries.

In 1803, the admiral Sir Home Riggs Popham publishes its Telegraphic Signals gold Marine Vocabulary , which made it possible the ships of the British navy to communicate between them with a system of flags.

The systems with repertories took a great importance starting from 1875, following the extension of the telegraph with or without wire. In the years 1870 to 1930, one found many repertories in the trade, inter alia:

• the quantified Telegraph code of Sittler

• the code Nilac
• the Telescand Codes (1914) for France
• the Day-book Wörterbuch de Friedmann with Berlin
• the Chiffrierbuch of Stern and Steiner (Vienna 1892)
• the Dizionario per corrispondenze in will cifra of Baravelli (Turin, 1896)
• the Nuovo Cifrario Mengarini (Rome, 1898)
• the Cifrario per the corrispendenza segreta of Cicero (Rome, 1889)
• the Diccionario Cryptographico (Lisbon, 1892)
• the Diccionario para has correspondencia secrete of Vaz Subtil (Lisbon, 1871)

At the court of Spain at the 17th century, the young girls were very supervised. They created a code with the movements of their range, it were limited but could dissimulate sentences like " you like me? ". Nowadays, them (small) repertories are still used. One thinks for example of the codes of the American police force, or of the code Q of the CB enthusiasts.

Types of repertories

There exist repertories with figures and others with letters. The advantage of the codes with letters is less their richness, superabundant, that the possibility of not choosing there, among all the possible sequences, that those which are pronounceable, allowed to ten letters for the price of a word by the telegraph, and lending less to the errors. The Bentley' S Complete Phrases Code Numbered is an ordered repertory which is at the same time with figures and letters (with the choice of the user):

Ordered repertories

That they are with figures or letters, the repertories are divided into two categories: ordered repertories and incoherent repertories.

One distinguishes two principal types from repertories. When, in the table of correspondence, the two lists (words and representations) are ordered both alphabetically or numerically, it is said that the repertory is ordered. Here an example of a page of a repertory with figures ordered:

In the ordered repertories, one uses the same table to quantify and decipher.

Incoherent repertories

To complicate the task of the cryptanalystes, one can use an incoherent word order (nonalphabetical order). One will then need two tables: to quantify and another to decipher. Such repertories are known as incoherent (one says also disordered or to broken sticks). Here an example of pages of an incoherent repertory with figures:

| width=" 10%" | || width=" 45%" | |}

Random links:

Lăutari | Club Atlético Belgrano | Philippe Chauveau (writer) | Piano-melodium | Championship of France of handball of Main road 2