involves a mixed alphabet as a prerequisite and is free from Gerolamo Cardano’s fatal defects. One form of encipherment is here exposed as follows. Given the plaintext “Ave Maria gratia plena” with Bellaso's IOVE table, the initials of each word are used as a key. The rest of the text letters are then enciphered with subsequent alphabets. Twenty-two years later Blaise de Vigenère described another form of autokey using a standard table primed by a single letter [Vigenère, f. 49.], which is more vulnerable than that of Bellaso's because of its regularity. Obviously by trying as primers all the alphabet letters in turn the cryptogram is solved after a maximum of 20 attempts. Vigenère himself candidely boasts the perfect regularity of his cipher: Bellaso's active involvement in the art for a long time is apparent. According to David Kahn, Bellaso bitterly writes in 1564, that somebody in that same year was ‘‘sporting his clothes and divesting him of his labors and honors.’’ This is a clear allusion to Della Porta, who printed the reciprocal table in 1563 without mentioning the true inventor. In the introduction of the book he lists thirteen qualities distinguishing his ciphers from other systems, and in a final section he claims priority for these four inventions: Encipher and decipher with a single countersign. Connect the words by an X or a Y. Mix the alphabets by a memorized keyword. Write the words using the letters of the alphabet, where other clerks employ a quantity of different characters or numbers. A challenge Bellaso challenged his detractors to solve some cryptograms encrypted according to his guidelines. He also furnished the following clue to help the solution of one of them: ‘‘The cryptogram contains the explanation why two balls, one in iron and one in wood, dropped from a high place will fall on the ground at the same time.’’ This is a clear statement of the law of the free-falling bodies forty years before Galileo. They were purportedly solved in 2018. References Alberti, Leon Battista, A Treatise on Ciphers [De componendis cyfris], edited by A. Buonafalce, foreword by D. Kahn, trans. by A. Zaccagnini, Galimberti Tipografi Editori, Torino 1997. Bellaso, Giovan Battista, La cifra del Sig. Giovan Battista Bel[l]aso, gentil’huomo bresciano, nuovamente da lui medesimo ridotta à grandissima brevità et perfettione, Venetia 1553. Bellaso, Giovan Battista, Novi et singolari modi di cifrare de l’eccellente dottore di legge Messer