Lewis Carroll's ciphers: The literary connections (Q2483908)

The five substitution cipher systems discussed in this paper were developed in the 19th century by Charles L. Dodgson, an Oxford lecturer who used the pseudonym Lewis Caroll. According to the author, the creation of the Caroll systems was intertwined with Dodgson's word game inventions, acrostics and anagrams. Some of the systems are simplified forms of the Vigenère cipher, another, a matrix cipher, is claimed by the author to be the first cipher making use of a mathematical group; the remaining systems are based on Beaufort's (Sestri's) cipher. Each system is described using small concrete examples. Regardig the security of the systems, the author mentions that, in the 19th century, only few people knew about Kasiski's method.