Crypto Wiki
Advertisement
This article does not cite any sources. Please help improve this article by adding citations to reliable sources. (May 2009)
File:Vigenère square.svg

Tabula recta

In cryptography, the tabula recta is a square table of alphabets, each row of which is made by shifting the previous one to the left. The term was invented by Johannes Trithemius in 1518, and used in his cipher.

Trithemius used the tabula recta to define a polyalphabetic cipher which was equivalent to Leon Battista Alberti's cipher disk except that the alphabets are not mixed. The tabula recta is often referred to in discussing pre-computer ciphers, including the Vigenère cipher and Blaise de Vigenère's less well-known autokey cipher. All polyalphabetic ciphers based on Caesar ciphers can be described in terms of the tabula recta.

In order to encrypt a plaintext, one locates the row with the first letter to be encrypted, and the column with the first letter of the key. The letter where the line and column cross is the ciphertext letter.

de:Tabula recta eo:Tabula recta es:Cifrado de Trithemius fr:Chiffre de Trithémius it:Tabula recta hu:Tabula recta nl:Tabula recta ro:Tabula recta sk:Tabula recta

Advertisement