Blaise de Vigenère (April 5, 1523 - 1596) was a French diplomat and cryptographer. The Vigenère cipher is so named due to the cipher being incorrectly attributed to him in the 19th century. engraving by Thomas de Leu, Bibliotheque Nationale, Paris. ... April 5 is the 95th day of the year in the Gregorian calendar (96th in leap years). ... Events April - Battle of Villalors - Forces loyal to Emperor Charles V defeat the Comuneros, a league of urban bourgeois rebelling against Charles in Spain. ... Events April 9 - Spanish troops capture Calais July 14 - King Dominicus (Domingos) Corea was behaded by the Portugese in Colombo Ceylon September 17 - The Spanish capture Amiens September 20 - Diego de Montemayor founded the city of Monterrey, Mexico. ... This page is about negotiations; for the board game, see Diplomacy (game). ... Pre-19th century Leone Battista Alberti, polymath/universal genius, inventor of polyalphabetic substitution (see frequency analysis for the significance of this -- missed by most for a long time and dumbed down in the Vigenère cipher), and what may have been the first mechanical encryption aid. ... The Vigenère cipher is named for Blaise de Vigenère (pictured), although the cipher had been invented earlier by Giovan Batista Belaso. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ...

Vigenère was born in the village of Saint-Pourçain. At age 17 he entered the diplomatic service, and remained there for 30 years, retiring in 1570. Five years into his career he was sent to the Diet of Worms as a very junior secretary. At age 24, he entered the service of the Duke of Nevers. In 1549 he visited Rome on a two-year diplomatic mission, and again in 1566. On both trips, he came in contact both with books on cryptography and cryptologists themselves. When Vigenère retired aged 47, he donated his 1,000 livres a year income to the poor in Paris. He married a Marie Varé. Events January 23 - The assassination of regent James Stewart, Earl of Moray throws Scotland into civil war February 25 - Pope Pius V excommunicates Queen Elizabeth I of England. ... The phrase Diet of Worms comes from the word Diet, a general assembly of the estates of the Holy Roman Empire and Worms, which is the name of the place the meeting was held. ... Nevers is a commune of central France, the préfecture (capital) of the Nièvre département, in the former province of Burgundy. ... Events July - Ketts Rebellion Francis Xavier arrives in Japan. ... Events January 7 - Pius V becomes Pope Selim II succeeds Suleiman I as Sultan of the Ottoman Empire Religious rioting in the Netherlands signifies the beginning of the Eighty Years War in the Netherlands. ... The Eiffel Tower has become the symbol of Paris throughout the world. ...

In his retirement, he was author of over twenty books including,

• Traicte de Cometes
• Traicte de Chiffres (1585)

In Traicte de Chiffres he described an autokey cipher he had invented, it was the first cipher of this type not to be trivially breakable. Events January 12 - The Netherlands adopts the Gregorian calendar Beginning of the Eighth War of Religion in France (also known as the War of the Three Henrys) August 8 - John Davis enters Cumberland Sound in quest for the North West Passage. ... An autokey cipher, or self-synchronizing stream cipher, is a cipher which incorporates the message (the plaintext) into the key. ...

Vigenère died of throat cancer in 1596. Events April 9 - Spanish troops capture Calais July 14 - King Dominicus (Domingos) Corea was behaded by the Portugese in Colombo Ceylon September 17 - The Spanish capture Amiens September 20 - Diego de Montemayor founded the city of Monterrey, Mexico. ...