Gerolamo Cardano

Gerolamo Cardano (1501 to 1576) was an Italian polymath, physician and mathematician whose work touches computing through cryptography and calculation. In 1550 he introduced the Cardan grille, a cryptographic writing tool in which a sheet with holes is laid over paper so that a hidden message is written through the holes and the gaps are filled with innocent text. He also described mechanical devices such as the combination lock, helped found probability, introduced the binomial coefficients and the binomial theorem to the West, and in his 1545 book Ars Magna published the solutions of cubic and quartic equations and made the first systematic use of negative numbers in Europe. He took a doctorate in medicine at the University of Padua in 1525.