cipher frequency table

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• Cipher disk — The Union Cipher Disk from the American Civil War was 3.75 inches (95 mm) in diameter and made of light yellow heavy card stock. It consisted of two concentric disks of unequal size revolving on a central pivot. The disks were divided along their …   Wikipedia

• Playfair cipher — The Playfair cipher or Playfair square is a manual symmetric encryption technique and was the first literal digraph substitution cipher. The scheme was invented in 1854 by Charles Wheatstone, but bears the name of Lord Playfair who promoted the… …   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

• 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

• 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

• Two-square cipher — The Two square cipher is a manual symmetric encryption technique. It was developed to ease the cumbersome nature of the large encryption/decryption matrix used in the four square cipher while still being slightly stronger than the Playfair cipher …   Wikipedia

• Transposition cipher — In cryptography, a transposition cipher is a method of encryption by which the positions held by units of plaintext (which are commonly characters or groups of characters) are shifted according to a regular system, so that the ciphertext… …   Wikipedia

• Letter frequency — The frequency of letters in text has often been studied for use in cryptography, and frequency analysis in particular. No exact letter frequency distribution underlies a given language, since all writers write slightly differently. Linotype… …   Wikipedia

• Four-square cipher — The Four square cipher is a manual symmetric encryption technique. It was invented by famous French cryptographer Felix Delastelle.The technique encrypts pairs of letters ( digraphs ), and thus falls into a category of ciphers known as… …   Wikipedia

• Keyword cipher — A keyword is a monoalphabetic substitution. A keyword is thought of and then the letters of the alphabet are assigned a letter after the keyword has been decided. When the number of letters in the keyword has been assigned their encoded version,… …   Wikipedia

• Nihilist cipher — In the history of cryptography, the Nihilist cipher is a manually operated symmetric encryption cipher originally used by Russian Nihilists in the 1880s to organize terrorism against the czarist regime. The term is sometimes extended to several… …   Wikipedia