In cryptography, a classical cipher is a type of cipher that was used historically but for the most part, has fallen into disuse. In contrast to modern...

In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code, or Caesar shift, is one of the simplest and most widely...

break the cipher. After the discovery of frequency analysis, nearly all such ciphers could be broken by an informed attacker. Such classical ciphers still...

In cryptography, a substitution cipher is a method of encrypting in which units of plaintext are replaced with the ciphertext, in a defined manner, with...

The Vigenère cipher (French pronunciation: [viʒnɛːʁ]) is a method of encrypting alphabetic text where each letter of the plaintext is encoded with a different...

pigpen cipher (alternatively referred to as the masonic cipher, Freemason's cipher, Rosicrucian cipher, Napoleon cipher, and tic-tac-toe cipher) is a geometric...

Historical pen and paper ciphers used in the past are sometimes known as classical ciphers. They include: Substitution cipher: the units of plaintext are...

cryptography, especially classical cryptography. Codes generally substitute different length strings of characters in the output, while ciphers generally substitute...

The Playfair cipher or Playfair square or Wheatstone–Playfair cipher is a manual symmetric encryption technique and was the first literal digram substitution...

The rail fence cipher (also called a zigzag cipher) is a classical type of transposition cipher. It derives its name from the manner in which encryption...

In cryptography, a transposition cipher (also known as a permutation cipher) is a method of encryption which scrambles the positions of characters (transposition)...

In classical cryptography, the bifid cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion...

occasion, ciphers have been broken through pure deduction; for example, the German Lorenz cipher and the Japanese Purple code, and a variety of classical schemes):...

In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. Invented by Lester S. Hill in 1929, it was the...

Bacon's cipher or the Baconian cipher is a method of steganographic message encoding devised by Francis Bacon in 1605. In steganography, a message is...

In classical cryptography, the running key cipher is a type of polyalphabetic substitution cipher in which a text, typically from a book, is used to provide...

polyalphabetic cipher is a substitution, using multiple substitution alphabets. The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though...

three categories of cipher used in classical cryptography along with substitution ciphers and transposition ciphers. In classical cryptography, a null...

A book cipher is a cipher in which each word or letter in the plaintext of a message is replaced by some code that locates it in another text, the key...

In cryptography, the ADFGVX cipher was a manually applied field cipher used by the Imperial German Army during World War I. It was used to transmit messages...

The Lorenz SZ40, SZ42a and SZ42b were German rotor stream cipher machines used by the German Army during World War II. They were developed by C. Lorenz...

trifid cipher is a classical cipher invented by Félix Delastelle and described in 1902. Extending the principles of Delastelle's earlier bifid cipher, it...

The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication...

The four-square cipher is a manual symmetric encryption technique. It was invented by the French cryptographer Felix Delastelle. The technique encrypts...

GC&CS Bletchley Park codename for any of several German teleprinter stream ciphers used during World War II. Enciphered teleprinter traffic was used between...

The Alberti cipher, created in 1467 by Italian architect Leon Battista Alberti, was one of the first polyalphabetic ciphers. In the opening pages of his...

An autokey cipher (also known as the autoclave cipher) is a cipher that incorporates the message (the plaintext) into the key. The key is generated from...

The Great Cipher (French: Grand chiffre) was a nomenclator cipher developed by the Rossignols, several generations of whom served the French monarchs...

and magazines. Other types of classical ciphers are sometimes used to create cryptograms. An example is the book cipher, where a book or article is used...

cryptography, a Feistel cipher (also known as Luby–Rackoff block cipher) is a symmetric structure used in the construction of block ciphers, named after the...