Giovan Battista Bellaso, a cryptographer from Brescia, publishes in 1553 La cifra del. Sig. Giovan Battista Bellaso, describing a polyalphabetic substitution cipher with a keyword: the letter to be encrypted is shifted a variable number of positions according to the corresponding letter of a repeated key. This is the cipher that, since the 19th century, has been universally known as the "Vigenère cipher." Blaise de Vigenère (1523–1596) described in 1586 a different cipher — the more sophisticated autokey cipher — but never claimed to have invented the fixed-key polyalphabetic cipher. The confusion was introduced by French mathematician Charles Luisant in 1917, who attributed Bellaso's cipher to Vigenère, and the error became entrenched in 20th-century textbooks. German cryptographer Friedrich Kasiski and British mathematician Charles Babbage would break it in the 19th century.