Depending on the orientation of the squares, horizontal or vertical, the cipher behaves slightly different. It is stronger than an ordinary Playfair cipher, but still easier The two-square cipher is also called 'double Playfair'. It uses a combination of a Polybius square and transposition of fractionated letters to encrypt The Bifid cipher was invented by the French amateur cryptographer Félix Delastelle around 1901, and is considered an important One of the more difficult variants is the double transposition cipher, which is equivalent to applying two columnar Many can be solved manuallyīy paper and pen. It is then read out line by line from the top.Ī lot of different transposition cipher variants exists, where the text is written in a particular pattern. The railfence cipher is a simple form of transposition cipher, where the text is written in a 'zig-zag' pattern. The columns are chosen in a scrambled order, decided by the encryption key. In a columnar transposition cipher, the message is written in a grid of equal length rows, and then read out column by column. It is a polygraphic substitution cipher, which encrypts pair of letters instead of single letters. The Playfair cipher was invented in 1854 by Charles Wheatstone, but named after lord Playfair who heavily promoted the use of the cipher. This cipher is similar to the Vigenère Autokey cipher, although it subtracts letters instead of adding them. The Beaufort Cipher is reciprocal (the encryption and decryption algorithms are the same). Subtracted from the key letter instead of adding them. It is similar to the Vigenère cipher, but uses a different 'tabula recta'. The Beaufort Cipher is named after Sir Francis Beaufort. Instead it begins using letters from the plaintext as key. It encrypt the first letters in the same way as an ordinary Vigenère cipher,īut after all letters in the key have been used it doesn't repeat the sequence. The Vigenère Autokey Cipher is a more secure variant of the ordinary Vigenère cipher. Gronsfeld ciphers can be solved as well through the Vigenère tool. The Vigenère cipher is an improvement of the Caesar cipher, by using a sequence of shifts instead of applying the same shift to every letter.Ī variant of the Vigenère cipher, which uses numbers instead of letters to describe the sequence of shifts, is called a Gronsfeld cipher. Despite being called the Vigenère cipher in honor of Blaise de Vigenère, it was actually developed by Giovan Battista Bellaso. The Vigenère cipher was invented in the mid-16th century and has ever since been popular in the cryptography and code-breaking community. To use Atbash, you simply reverse the alphabet, so A becomes Z, B becomes Y and so on. It is believed to be the first cipher ever used. The Atbash Cipher is a really simple substitution cipher that is sometimes called mirror code.

Monoalphabetic Substitution Cipher Tool.The more difficult variant, without word boundaries, is called a Patristocrat. If it contains word boundaries (spaces and punctuation), it is called an Aristocrat. Each letter is substituted by another letter in the alphabet. The monoalphabetic substitution cipher is one of the most popular ciphers among puzzle makers.

Atbash cipher decryption tool