Johannes Trithemius (February 1, 1462 - December 13, 1516), born Johann Heidenberg, was a German Benedictine abbot and a polymath active in the German Renaissance, as a lexicographer, chronicler, cryptographer and occultist. He took considerable influence on the development of early modern and modern occultism; among his students were Heinrich Cornelius Agrippa and Paracelsus. His most famous work, Steganographia (written 1499; published, 1606), is in three volumes, and appears to be about magic, specifically, about using spirits to communicate over long distances. Since the publication of the decryption key (Trithemius cipher) to the first two volumes in 1606, they have been known to be actually concerned with cryptography and steganography. 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 Trithemius in 1508, and used in his Trithemius cipher. He died in 1516 at the age of 54.