ciphertext letter frequencies

См. также в других словарях:

• Vigenère cipher — The Vigenère cipher is a method of encrypting alphabetic text by using a series of different Caesar ciphers based on the letters of a keyword. It is a simple form of polyalphabetic substitution.The Vigenère (pronEng|ˌviːdʒɪˈnɛəɹ, veedj ih nair )… …   Wikipedia

• частоты встречаемости букв в шифртексте — — [http://www.rfcmd.ru/glossword/1.8/index.php?a=index d=23] Тематики защита информации EN ciphertext letter frequencies …   Справочник технического переводчика

• cryptology — cryptologist, n. cryptologic /krip tl oj ik/, cryptological, adj. /krip tol euh jee/, n. 1. cryptography. 2. the science and study of cryptanalysis and cryptography. [1635 45; < NL cryptologia. See CRYPTO , LOGY] * * * Introduction …   Universalium

• Index of coincidence — In cryptography, coincidence counting is the technique (invented by William F. Friedman[1]) of putting two texts side by side and counting the number of times that identical letters appear in the same position in both texts. This count, either as …   Wikipedia

• Frequency analysis — In cryptanalysis, frequency analysis is the study of the frequency of letters or groups of letters in a ciphertext. The method is used as an aid to breaking classical ciphers.this is wrong is based on the fact that, in any given stretch of… …   Wikipedia

• Substitution cipher — In cryptography, a substitution cipher is a method of encryption by which units of plaintext are replaced with ciphertext according to a regular system; the units may be single letters (the most common), pairs of letters, triplets of letters,… …   Wikipedia

• Smithy code — This article refers to a cipher used in 2006 by Mr Justice Peter Smith and inserted into his judgment in the litigation concerning alleged plagiarism by Dan Brown. For the prisoner code invented by Capt. Smitty Harris in 1965, see Tap Code. The… …   Wikipedia

• Permutation cipher — In classical cryptography, a permutation cipher is a transposition cipher in which the key is a permutation.To apply a cipher, a random permutation of size e is generated (the larger the value of e the more secure the cipher). The plaintext is… …   Wikipedia

• Rotor machine — In cryptography, a rotor machine is an electro mechanical device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state of the art for a brief but prominent period of history; they were in widespread use… …   Wikipedia

• Japanese cryptology from the 1500s to Meiji — The cipher system that Uesugi used is basically a simple substitution usually known as a Polybius square or “checkerboard.” The i ro ha alphabet contains forty eight letters, so a seven by seven square is used, with one of the cells left blank.… …   Wikipedia

• Caesar cipher — The action of a Caesar cipher is to replace each plaintext letter with one fixed number of places down the alphabet. This example is with a shift of three, so that a B in the p …   Wikipedia