Editing Tabula recta (section)

=== Improvements ===
In 1553, an important extension to Trithemius's method was developed by [[Giovan Battista Bellaso]], now called the [[Vigenère cipher]].<ref>Salomon, Coding for Data, page 249</ref> Bellaso added a key, which is used to dictate the switching of cipher alphabets with each letter. This method was misattributed to [[Blaise de Vigenère]], who published a similar [[autokey cipher]] in 1586.

The classic Trithemius cipher (using a shift of one) is equivalent to a Vigenère cipher with ABCDEFGHIJKLMNOPQRSTUVWXYZ as the key. It is also equivalent to a Caesar cipher in which the shift is increased by 1 with each letter, starting at 0.